Telescoping magnetic ball bar test gage
- Pleasanton, CA
A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengageable servo drives which cannot be clutched out. Two gage balls (10, 12) are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit (14) and a rigid member (16, 18, 20, 22, 24). One gage ball (10) is secured by a magnetic socket knuckle assembly (34) which fixes its center with respect to the machine being tested. The other gage ball (12) is secured by another magnetic socket knuckle assembly (38) which is engaged or held by the machine in such manner that the center of that ball (12) is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball (10). As the moving ball (12) executes its trajectory, changes in the radial distance between the centers of the two balls (10, 12) caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly (50, 52, 54, 56, 58, 60) actuated by the parallel reed flexure unit (14). Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball (10) locations, thereby determining the accuracy of the machine.
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Number(s):
- US 4435905
- OSTI ID:
- 864908
- Country of Publication:
- United States
- Language:
- English
Similar Records
Telescoping magnetic ball bar test gage
Automatic ball bar for a coordinate measuring machine
Related Subjects
magnetic
ball
bar
gage
determining
accuracy
machine
tools
including
robots
measuring
machines
non-disengageable
servo
drives
clutched
balls
10
12
held
separated
fixture
allows
relative
radial
motional
freedom
lateral
comprises
parallel
reed
flexure
unit
14
rigid
16
18
20
22
24
secured
socket
knuckle
assembly
34
fixes
center
respect
tested
38
engaged
manner
directed
execute
prescribed
trajectory
equidistant
fixed
moving
executes
changes
distance
centers
caused
inaccuracies
determined
measured
linear
variable
differential
transformer
lvdt
50
52
54
56
58
60
actuated
measurements
quickly
easily
multiple
trajectories
locations
ball bar
relative radial
radial distance
machine tools
measuring machine
machine tool
differential transformer
variable differential
linear variable
measuring machines
lateral motion
telescoping magnetic
servo drive
magnetic ball
/33/901/