Method and apparatus for use in co-ordinate measuring machines

• US 4,571,847 A
• Filed: 12/04/1984
• Issued: 02/25/1986
• Est. Priority Date: 02/07/1977
• Status: Expired due to Term

• Current Assignee: Renishaw PLC
• Original Assignee: Renishaw PLC, Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: McMurtry, David R.
• Primary Examiner(s): Stearns, Richard R.
• Application Number:
  US06/678,363
• Time in Patent Office: 448 Days
• Field of Search: 33/1 D, 33/23 K, 33/169 R, 33/172 E, 33/174 L, 33/174 P, 33/174 PC, 33/174 TD, 74/813 R, 74/813 L, 74/816, 74/817, 74/826
• US Class Current: 33/503
• CPC Class Codes: G01B 7/008 using coordinate measuring machines
• CPC Class Codes: Y10T 74/1418 Preselected indexed position
• CPC Class Codes: Y10T 74/1476 with means to axially shift shaft

Abstract

In a co-ordinate measuring machine a probe is connected to the head of the machine by a pivotal arm, and the orientation of the probe is changed by moving the head so that the arm engages a fixed structure and a moment is applied to the arm which is thereby caused to turn and present the probe in the required orientation.

Claims

1. A device for mounting a tool in a machine, the tool having a supported end and a free end which, in use, performs an operating function, said device comprising a first member adapted to be secured to the machine, a second member to which said supported end is connected, the members having an axis, one of the members having a group of more than three first support elements arranged about said axis, the other member having a group of only three second support elements arranged about said axis, the members being relatively rotatable about said axis to establish approximate axial alignment between said three second elements and a selected three of the first elements, the first elements having seat surfaces, the second elements having seat surfaces confronting the seat surfaces of the first elements when the alignment is established, the members being movable relatively axially to establish engagements between confronting ones of said surfaces of the first and second elements, the surfaces of the elements of one of said groups defining pairs of convergent surfaces on which the surfaces of the elements of the other group are seatable during the engagements thereby to locate the members positively on the other and determine the angular and radial relationship of the members, and the surfaces of the elements of each of said groups are convex in respective first planes perpendicular to respective second planes through said axis, and the surfaces of the elements of at least one of the groups are additionally convex in respective said second planes.

2. A device according to claim 1, wherein the surfaces of said at least one of the groups are spherical.

3. A device for mounting a tool in a machine, the tool having a supported end and a free end which, in use, performs an operating function, said device comprising a first member adapted to be secured to the machine, a second member to which said supported end is connected, the members having an axis, one of the members having a group of more than three first support elements arranged about said axis, the other member having a group consisting solely of three second support elements equispaced circumferentially about said axis, the members being relatively rotatable about said axis to establish approximate axial alignment between said second elements and selected three equispaced pairs of the first elements, the first elements defining around the axis, pairs of converging seat surfaces, the second elements having seat surfaces confronting the seat surfaces of said three selected pairs of the first elements when the alignment is established, the members being movable relatively axially to establish engagements between the confronting seat surfaces of the first and second elements thereby to locate the members positively one with respect to the other and determine the angular and radial relationship of the members, said seat surfaces of both the first and second elements being convex in a first plane perpendicular to a second plane which passes radially through said axis, thereby to constrain the second elements against relative movement in said first plane, and the seat surfaces of one group of elements being convex in said second plane and being shaped and arranged relative to the seat surfaces of the other group of elements to permit, at each of said three locations, relative movement of the second elements in said second plane.