Stylus attachment for a metrological instrument

A stylus assembly for a metrological instrument comprising a stylus and a stylus support contactable through kinematic mounting means defining a kinematic mounting plane,

• one of the stylus and the stylus support comprising:
• a resiliently biassed member operable to act on a part of the other of the stylus and the stylus support to hold the stylus and the stylus support together in a stylus-held state;
• and
• first and second release members which are movable relative to each other to change at least one of the position a the shape of the resiliently biassed member so that the resiliently biassed member is a stylus-released state and does not act on said part and the stylus and the stylus support can be separated from each other or moved together.

A component for a stylus assembly for a metrological instrument, the component being one of a stylus and a stylus support, said component comprising:

• kinematic mounting means for contacting a corresponding kinematic mounting means on the other of the stylus and the stylus support to define a kinematic mounting plane;
• a resiliently biassed member for acting, when in a stylus-held state, on a part of the other of the stylus and the stylus support to hold the stylus and the stylus support together;
• and
• first and second release members which are movable relative to each other to change the position or the shape of the resiliently biassed member to a stylus-released state in which the resiliently biassed member does not act on the said part and the stylus may be separated from or moved towards a stylus support.

A metrological instrument for measuring a characteristic of a measurement surface, having:

• a main body;
• pivot mountings located on said main body;
• and
• a stylus assembly coupled to the main body of the metrological instrument via said pivot mountings so that the stylus assembly is pivotable about a pivot axis in response to the characteristic of the measurement surface, said stylus assembly comprising a stylus and a stylus support releasably held together by an attachment force generated by the action of a resiliently biassed surface of a part of one of the stylus and the stylus support on a reaction surface of the other of the stylus and the stylus support,
• wherein the resiliently biassed surface and the reaction surface are arranged so that movement of the stylus and the stylus support away from each other causes relative movement of the resiliently biassed surface over the reaction surface and also causes movement of the resiliently biassed surface against its resilient bias until a relative position is reached in which the attachment force is no longer generated.

A stylus assembly for a metrological instrument, comprising a stylus and a stylus support contactable through kinematic mounting means defining a kinematic mounting plane,

• said stylus support comprising a first coupling surface and a projection projecting from said first coupling surface, said projection having a first portion and a second portion, adjacent said first portion and between said first portion and said first coupling surface, whose cross-sectional area decreases in the direction towards said first coupling surface,
• and said stylus comprising a second coupling surface having an opening for receiving said projection and two resiliently deformable members which in their relaxed state, obstruct said opening, and two release members which are movable relative to each other to change the shape of at least one of the two resiliently deformable members,
• said resiliently deformable members and said release members being arranged so that, when said stylus assembly is assembled, said resiliently deformable members act on the surface of said second portion to hold the stylus and the stylus support together in a stylus-held state and said release members are movable to alter the shape of at least one of the resiliently deformable members to a stylus-released state of the resiliently deformable members in which the resiliently deformable members do not act on said second portion and the stylus and the stylus support can be separated from each other or moved together in said stylus-released state.

A metrological instrument for measuring a characteristic of a measurement surface, having a stylus assembly comprising a stylus and a stylus support contactable through kinematic mounting means defining a kinematic mounting plane,

• one of the stylus and the stylus support comprising:
• a resiliently biassed member operable to act on a part of the other of the stylus and the stylus support to hold the stylus and the stylus support together in a stylus-held state;
• and
• first and second release members which are movable relative to each other to change at least one of the position and the shape of the resiliently biassed member to a stylus-released state so that the resiliently biassed member does not act on said part and the stylus and the stylus support can be separated from each other or moved together.

A metrological instrument for measuring a characteristic of a measurement surface, having:

• a main body;
• pivot mountings located on said main body;
• and
• a stylus assembly coupled to the main body of the metrological instrument via said pivot mountings so that the stylus assembly is pivotable about a pivot axis in response to the characteristic of the measurement surface, said stylus assembly comprising a stylus and a stylus support, one of the stylus and the stylus support comprising:
• a resiliently biassed member operable to act on a part of the other of the stylus and the stylus support to hold the stylus and the stylus support together in a stylus-held state;
• and
• first and second release members which are movable relative to each other to change at least one of the position and the shape of the resiliently biassed member to a stylus-released state in which the resiliently biassed member does not act on said part and the stylus and the stylus support can be separated from each other or moved together.

A metrological instrument for measuring a characteristic of a measurement surface, said metrological instrument having:

• a main body;
• pivot mountings located on said main body;
• and
• a stylus assembly coupled to the main body of the metrological instrument via said pivot mountings so that the stylus assembly is pivotable about a pivot axis in response to the characteristic of the measurement surface, said stylus assembly comprising a stylus and a stylus support,
• said stylus support comprising a first coupling surface and a projection projecting from said first coupling surface, said projection having a first portion and a second portion, adjacent said first portion and between said first portion and said first coupling surface, whose cross-sectional area decreases in the direction towards said first coupling surface,
• and said stylus comprising a second coupling surface having an opening for receiving said projection and two resiliently deformable members which, in their relaxed state, obstruct said opening and two release members which are movable relative to each other to change the shape of at least one of the two resiliently deformable members,
• said resiliently deformable members and said release members being arranged so that, when said stylus assembly is assembled, said resiliently deformable members act on the surface of said second portion to hold the stylus and the stylus support together and said release members are movable to alter the shape of at least one of the resiliently deformable members so that the resiliently deformable members do not act on said second portion and the stylus and the stylus support can be separated from each other or moved together.

A stylus assembly for a metrological instrument, comprising a stylus and a stylus support, said stylus support comprising:

• a first coupling surface;
• a first projection projecting from said first coupling surface, said first projection having a cylindrical first portion, circular in cross-section and a second portion, adjacent said first portion and between said first portion and said first coupling surface, whose cross-sectional area decreases in the direction towards said first coupling surface,
• a second projection projecting from said first coupling surface;
• and
• three bearing balls provided on said first coupling surface;
• and said stylus comprising:
• a disc having two opposing sides, one opposing side defining a second coupling surface;
• three grooves located on said coupling surface;
• a first opening in said disc;
• a second opening in said disc;
• a rod mounted in said second opening so that said rod protrudes from the other opposing side of said disc;
• a stylus tip mounted at one end of the rod;
• a recess formed in the other end of the rod;
• a flange located near the other end of the rod;
• and
• a resilient member having first and second end portions shaped so that the first and second end portions cross over and are each coupled by a respective attachment portion to an intermediate portion, the intermediate portion being captured between said flange and said other opposing side of said disc to secure the resilient member, said attachment portions being arranged to obstruct said first opening in their relaxed state and said end portions being arranged to project away from said other opposing side of said disc;
• wherein said second projection is adapted to engage the recess in said rod to provide coarse alignment between said stylus and said stylus support;
• each of said bearing balls is arranged to engage a respective one of said grooves to provide precision alignment between said stylus and said stylus support;
• said end portions of said resilient member are manually operable to deform said resilient member so that said attachment portions do not obstruct said first opening and the first projection can freely move in and out of said first opening;
• said attachment portions, when said stylus assembly is assembled, act on said second portion of said projection to generate an attachment force to hold said stylus and said stylus support together;
• and
• movement of said stylus and said stylus support away from each other causes said attachment members to traverse the surface of said second portion until said attachment members act on the surface of said first portions and said attachment force is no longer generated.

A metrological instrument for measuring a characteristic of a measurement surface, having a stylus assembly comprising a stylus and a stylus support,

• said stylus support comprising:
• a first coupling surface;
• a first projection projecting from said first coupling surface, said first projection having a cylindrical first portion, circular in cross-section and a second portion, adjacent said first portion and between said first portion and said first coupling surface, whose cross-sectional area decreases in the direction towards said first coupling surface,
• a second projection projecting from said first coupling surface;
• and
• three bearing balls provided on said first coupling surface;
• and said stylus comprising:
• a disc having two opposing sides, one opposing side defining a second coupling surface;
• three grooves located on said coupling surface;
• a first opening in said disc;
• a second opening in said disc;
• a rod mounted in said second opening so that said rod protrudes from the other opposing side of said disc;
• a stylus tip mounted at one end of the rod;
• a recess formed in the other end of the rod;
• a flange located near the other end of the rod;
• and
• a resilient member having first and second end portions shaped so that the first and second end portions cross over and are each coupled by a respective attachment portion to an intermediate portion, the intermediate portion being captured between said flange and said other opposing side of said disc to secure the resilient member, said attachment portions being arranged to obstruct said first opening in their relaxed state and said end portions being arranged to project away from said other opposing side of said disc;
• wherein said second projection is adapted to engage the recess in said rod to provide coarse alignment between said stylus and said stylus support;
• each of said bearing balls is arranged to engage a respective one of said grooves to provide precision alignment between said stylus and said stylus support;
• said end portions of said resilient member are manually operable to deform said resilient member so that said attachment portions do not obstruct said first opening and the first projection can freely move in and out of said first opening;
• said attachment portions, when said stylus assembly is assembled, act on said second portion of said projection to generate an attachment force to hold said stylus and said stylus support together;
• and
• movement of said stylus and said stylus support away from each other causes said attachment members to traverse the surface of said second portion until said attachment members act on the surface of said first portions and said attachment force is no longer generated.