Lapping tools
AssigneesAutomobiles Citroen, Societe dite: Automobiles Peugeot
InventorPierre A. Largeteau
Life of this patent
Estimating the term…
Abstract
A tool for lapping internal surfaces of holes. Lapping tools conventionally have an expandable working portion for variable diameter operation. Known tools tend to expand in a barrel shape leading to inaccurate lapping. The invention seeks to avoid this by providing a working portion of a tubular tool with slots in a plurality of rows each having several slots. Slots in each row are staggered relative to those in adjacent rows.
Claims11
A lapping tool comprising:
- an elongated tubular member having a working portion formed at one end thereof with a substantially cylindrical abrasive external surface and a frusto-conical internal surface, said working portion being provided with a plurality of rows of slots lying along respective generatrices and angularly spaced all around said working portion, said slots being throughgoing between said surfaces and elongated along the respective generatrices with the slots of each row being spaced apart, the slots of each row being staggered relative to the slots of adjacent rows such that a slot of each row lies opposite a space between slots of an adjoining row, said slots having lengths greater than that of said spaces along the respective generatrices;
- and
- a control rod having a frusto-conical portion axially slidable within said working portion and cooperating with said frusto-conical internal surface for adjusting the diameter of said working portion by relative axial displacement of said rod and said member.
In a lapping machine comprising a spindle, a lapping tool connected to said spindle, and an expansion rod operable to vary the diameter of said tool, the improvement wherein said tool comprises:
- an elongated tubular member having a working portion formed at one end thereof with a substantially cylindrical abrasive external surface and a frusto-conical internal surface, said working portion being provided with a plurality of rows of slots lying along respective generatrices and angularly spaced all around said working portion, said slots being throughgoing between said surfaces and elongated along the respective generatrices with the slots of each row being spaced apart, the slots of each row being staggered relative to the slots of adjacent rows such that a slot of each row lies opposite a space between slots of an adjoining row, said slots having lengths greater than that of said spaces along the respective generatrices;
- a control rod having a frusto-conical portion axially slidable within said working portion and cooperating with said frusto-conical internal surface for adjusting the diameter of said working portion by relative axial displacement of said rod and said member;
- means for connecting said tubular member to said expansion rod;
- and
- means for fixing said control rod to said spindle to prevent axial movement of the frusto-conical portion of the control rod.
Dependencies are inferred from the claim text.