Precision extended-length micrometer with displacement meter probe adapter

A measurement system comprising:

• an extended-length cylindrical-beam type micrometer having a measuring range of over 12 inches, said micrometer including:
• a cylindrical beam having its longitudinal axis oriented parallel to and spaced from a planar surface, said beam having first and second end portions and a middle portion, and having first and second foot means disposed at said first and second end portions, respectively, for supporting said first and second end portions on said planar surface, said beam having a length of greater than 24 inches, and further having at least one slot extending longitudinally along the outside surface of said beam over at least said middle portion;
• a headstock fixedly attached to said beam at the second end portion, said headstock having a measuring anvil and a rotatable spindle with a graduated dial which cooperate to move said headstock anvil less than 2 inches along its longitudinal axis and parallel to the longitudinal axis of said beam;
• a tailstock having a base moveably attached to said cylindrical beam at said middle portion, said tailstock base including means for clamping said tailstock to said beam by engaging with said beam slot, said tailstock base surrounding only a first portion of the circumference of said beam when moved longitudinally along the axis of and over the surface of said beam, said tailstock including a measuring anvil assembly, said measuring anvil assembly having a fixed base coupled to an elongated moveable anvil head by a spring mechanism such that said anvil head is positioned with its longitudinal axis parallel to the longitudinal axis of said headstock anvil and such that said anvil head is adapted to move along its longitudinal axis, said tailstock further including a contact block attached to one surface of said anvil head such that a major surface of said contact block is disposed perpendicular to both the surface of said anvil head and its longitudinal axis;
• and
• pedestal means for supporting said cylindrical beam on said planar surface at said middle portion, said pedestal means contacting said beam only at a second portion of the circumference of said beam other than said first portion such that said tailstock is adapted to be moved over the surface of said beam throughout said middle portion without contacting said pedestal means, and such that said micrometer has a measuring range from zero to at least 12 inches without removing said pedestal means;
• said system further comprising:
• a displacement meter adapted to measure distances as a function of pressure applied to a probe;
• a probe having a probe body and moveable tip, said probe coupled to said displacement meter and adapted to convert mechanical pressure applied to said tip into an electrical parameter which can be measured by said displacement meter, said probe being affixed to said tailstock such that a majority of said probe body extends out of said tailstock and such that said tip engages said contact block perpendicular to said major surface such that said tip moves along an axis parallel to said longitudinal axis of said anvil head.

An adapter assembly for adapting a cylindrical beam-type mechanical micrometer, such as a Pratt & Whitney supermicrometer Model A, for use with an electrical displacement meter, said micrometer including a tailstock having a housing moveably attached to said cylindrical beam, said tailstock having a measuring anvil assembly disposed within an upper portion of said housing, said anvil assembly having a fixed base coupled to an elongated moveable anvil head by a spring mechanism such that said anvil head is positioned with its longitudinal axis parallel to the longitudinal axis of said beam and such that said anvil head is adapted to move along its longitudinal axis, said anvil head having upper and lower planar surfaces, said adapter assembly comprising:

• a contact block constructed and arranged to freely fit within said tailstock housing and to be attached to said lower surface of said anvil head, said contact block having a front planar surface and having a bottom planar surface constructed to be at precisely a 90.degree. angle to said front planar surface, said bottom planar surface adapted to be attached to said lower surface of said tailstock anvil head within said tailstock housing such that its front planar surface is positioned at precisely a 90.degree. angle to said lower surface of said tailstock anvil head, and such that its front planar surface is positioned at precisely a 90.degree. angle to said axis of movement of said anvil head such that said contact block freely moves within said tailstock housing with the movement of said anvil head;
• a sufficient amount of cyanoacrylate-type glue for gluing said bottom planar surface of said contact block to said lower surface of said tailstock anvil head such that said contact block is adapted to be securely affixed thereto;
• and
• a probe clamp for mounting a displacement meter probe to the tailstock housing, said probe clamp constructed and arranged to be securely affixed to an external surface of the tailstock housing such that the majority of a body portion of said probe remains external to said tailstock housing while a tip portion of said probe protrudes within said tailstock housing and engages the front planar surface of said contact block affixed to the lower surface of said tailstock anvil head, and such that the axis of movement of said probe tip is at precisely a 90.degree. angle to the front planar surface of said contact block.

A method for adapting a cylindrical beam-type mechanical micrometer for use with an electronic displacement meter having a remote probe, said remote probe having a body and a moveable tip, said micrometer having a cylindrical beam, a headstock fixedly attached to said beam, a tailstock moveably attached to said beam, said tailstock having a housing, a measuring anvil assembly disposed with said housing, and a cover enclosing said anvil assembly, said tailstock anvil assembly having a fixed base coupled to an elongated moveable anvil head wherein said anvil head is positioned such that its longitudinal axis is parallel to the longitudinal axis of said beam and such that said anvil head is adapted to move along its longitudinal axis, the method comprising the steps of:

• removing the cover from the tailstock housing;
• removing the anvil assembly from the tailstock housing;
• gluing a contact block to one surface of the anvil head such that a major surface of the contact block is disposed perpendicular to both the surface of the anvil head and to the longitudinal axis of said anvil head;
• providing an aperture for a remote probe within the tailstock housing;
• attaching a probe clamp to the outside of the tailstock housing;
• replacing the anvil assembly within the tailstock housing;
• clamping the body of the probe to the outside of the tailstock housing with the probe clamp such that the tip of the probe extends within the housing and engages the major surface of the contact block, and such that the axis of movement of the probe tip is perpendicular to the major surface of the contact block;
• and
• replacing the cover on the tailstock housing.

A method of modifying a cylindrical beam-type mechanical micrometer such that it is adapted to measure objects of over 24 inches in length, said micrometer having:

• an original cylindrical beam of less than 36 inches in length;
• at least two supporting feet, each located approximately at each end of the beam, for supporting the beam on a surface;
• a headstock fixedly attached to said beam;
• a tailstock moveably attached to said beam, said tailstock including a tailstock housing substantially encircling said beam, a measuring anvil assembly disposed within said tailstock housing, and a clamping mechanism disposed on a lower portion of said tailstock housing, the method comprising the steps of:
• disassembling the original cylindrical beam from the headstock and the tailstock;
• replacing the original cylindrical beam with an extended cylindrical beam having a length of over 36 inches;
• machining a pair of longitudinal slots in the extended beam which are positioned approximately on opposing sides of the beam and which extend over at least the measuring range of the beam;
• machining the tailstock to remove the lower portion of the housing and the clamping mechanism such that the tailstock housing no longer encircles the beam, such that an upper portion of the housing is adapted to rest on said beam, and such that two opposing side portions extend down the sides of the beam at least as far as the position of the longitudinal slots;
• constructing a tailstock fastener for attachment to each side portion of the tailstock housing, such that one portion of the tailstock fastener disposed on the inner side of the housing is adapted to be slideably disposed within the longitudinal slots, and such that another portion of the tailstock fastener disposed on the outer side of the housing is adapted to be manually engaged to clamp the tailstock securely to the bean by engaging with the longitudinal slots;
• providing a least one center pedestal for supporting the beam at approximately a middle portion of the beam;
• assembling the headstock, the extended beam, and the center pedestal such that the beam is disposed on a planar surface and is supported on the surface at each end of the beam by said two support feet, and approximately in a middle portion of the beam by the center pedestal;
• and
• attaching the tailstock to the beam such that it moves along an upper surface of the beam and freely moves over the center pedestal when the tailstock fasteners are disengaged, and such that it is securely affixed to the beam when the tailstock fasteners are engaged.