Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a height gage of a type to be attached
to a digital readout.
Height gages having generally horizontally arranged base and a -
vertical column extending upwardly from the base and which are at-
tached to a digital readout have been known, and means carrying a
probe have been vertically adjusted on the column by some anti-fric~
tion means such as ball bearings or the like. These are expensive to
construct and have difficulties in use.
The present invention provides a height gage which comprises a ~
10 generally horizontally disposed base and a generally vertically dis- -
posed column extending upwardly therefrom, said column having a plu- -
rallty of vertically disposed surfaces, a slide embracing said
column and presenting slide surfaces to the surfaces of said column,
said slide being expandible and formed by a plurality of plates,
means connecting said plates, said means being of a character to flex
and cause expansion of the embracing slide upon the introduction of
fluid pressure between the surfaces of said slide and column to form
a frlctionless fluid bearing and subsequent contraction in the absence
of such fluid pressure to grip the column, said slide surfaces having
a plurality of fluid openings, and means to supply fluid to said
fluid openings to expand said slide.
This invention thus provides an improved linear motlon of a ~!
probe carrier slide along the vertical length of a stable reference
surface provided by the vertical column, the slide being easily
positioned, with minimal effort, as it moves on a frictionless fluid
bearing In the preferred embodiment, fluid e.g. air bearings are
securely anchored into a prismat~c configuration to ensure accuracy
of movement of the slide along the vertical effective measuring range
of the column, which is suitably formed of granite, and which has
means for the inclusion of a loc~ing and fine ad~ustment for accu-
rately positioning the slide. A tapered probe means for the measure-
ment of holes of different diameters is preferably rigidly attached
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to the fluid bearing slide.
In the accompanying drawings:
Fig. 1 is a perspective view of the height gage;
Flg. 2 is a fragmental perspective view of the slide and
column;
Fig. 3 is a sectional view through the column ~ust above the
slide with the slide also partly in section and showing the upper
end of the slide;
Fig. 4 1s a sectional view through the air conduits of the
slide of Fig. 3,
Fig. 5 is a perspective view of one of the plates of the slide;
Flg. 6 is a fragmental elevation showing the probe and its
aligning block;
Fig. 7 is a sectional view on line 7-7 of Fig. 6 and illustra-
ting the curved opposite edges of the probe;
Fig. 8 is a schematic view similar to Fig. 3 showing the
sllde gripping the column; and
Fig. 9 is a vlew similar to Fig. 8 showing the slide expanded.
The base 10 of the height gage comprises a relatively heavy
block of metal with a front 11, back 12 and sides -13. The edges
of the base are tapered from the top and bottom to provide a rib 14
extending about the sides of the base. The base i8 also recessed
at its front portion as at 15 for movement close to the work to be
measured.
A slide 65 has a hollow center receiving the granite column 60
and is of rectangular shape in cross section being formed of four
plates such as shown individually in Fig. 5. A top plan view with
a broken away section of this slide is shown in Fig. 3 where it
will be seen in the broken away or sectioned portion at the upper
right-hand corner that there is an opening 66, leading from a
recessed portion 67 in the corner of the plate, through which a
clamping screw 68 extends having a much smaller diameter than the
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opening 66. This screw extends lnto a threaded opening in the ad-
~acent plate as at 69 sufficiently so as to provide the bearing
asEembly clearance 73 between ad~acent plates, and there is a similar
connectlon between each of the ad~acent plates at both the top,
bottom and intermediate portions of this slide. An ad~usting screw
70 serves to hold the clamp screw 68 in the desired position as it
extends through the larger opening 66. Compliance of ad~acent
plates to a trapezoidal or out of squareness condition of the column
60 is accommodated by a hinge effect created by the flexing of the
clamp screw 68 within the opening 66 allowed by the assembly
clearance 73. Operating clearance 75 (Fig. 4) is provided by air
pressure from the air outlet openings 78 (Figs. 4 and 5) and this .-
clearance may be adjusted at diagonal opposite corners of the slide
by the ad~usting screw 70 acting as an abutment against the clamp
screw 68 as it extends through the larger opening 66, with the
column and slide under air pressure.
Extending laterally through each of the plates of the slide are
air condults 71 (Flg. 4) which terminate in each of the plates.
Further there are openings 72 in the inner side face of each of the
plates connected to the conduits 71 as can be seen in Fig. 4 so that
when the plates are placed in a relation of one edge of a plate
against the inside face of an ad~acent plate, the opening 72 will
align with the conduit 71 of the ad~acent plate. Thus, in the as-
sembly of four plates as shown in Fig. 4, there will be a complete
air circuit in a rectilinear path for air under pressure. A clrcuit -~
such as this is provided at both the top and bottom of the slide and
externally interconnected ~y conduit 74 extending vertically along
the slide 65 w~th air admitted as at 76 (Fig. 2~. A recess is
located at the end of each of these air conduits 71 and receives an
O-ring 77 to seal the conduits 71 in one plate and the opening 72
which leads to the conduit in the next plate. These O-rings are
under compression to provide the seal by means of the clamping screws
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68 above described and shown in Fig. 3. From each of the conduits
there is provided air outlet openings 78 (Figs. 4 and 5) on the inner
surface of each of the plates from which there extends radial chan-
nels 79 and 80 in a crossing fashion and leading to a circular chan-
nel 81 for the distribution of air inwardly against the granite
column 60 under air pressure when admitted as at 76. This pressure
of air against the granite column will cause the screws 68 at the
diagonal opposite corners to flex slightly an amount equal to
clearance 75, (Fig. 4) along the width of the plate, and thus, with
this air bearing, the slide may be easily moved along the column
without friction. Locking of the slide in position may be had
through its fine ad~usting screw by a knob in back of the slide to
cause two spring loaded half nuts to close against the adjusting
screw. When the air pressure is shut off as at 76, the slide con-
tracts on the column 60.
It will be observed, as seen in Fig. 9, that there is a flexing
of the screw 68 which has clearance thru the opening 66 thru which
it extends. Thus, as the air is inserted in this rectangular slide,
the plates expand from clamping the granite column 60 and provide a
frlctionless bearing. This expansion occurs by reason of the flexing
of the threaded connecting means 68. In Fig. 8 the slide is shown
with no air pressure applied, while Fig. 9 indicates the air pressure
applied. Connecting screws 68 in Fig. 8 are indicated as in a
straight line or having a straight axis, and in this position the
slide engages the column and will not move along the column. The
spacing of the plates is largely exaggerated for clarity. For ex-
ample, when the pressure is applied, the plate 100 will move as shown
in Fig. 9 in the direction of arrow 108 to flex the screw 68.
Typically the plate will move as shown at B substantially 0.01778mm
with reference to the column as shown in the illustration. Plate
100 will also move as shown by arrow 101. At the same time the
pressure will move all of the plates similarly. Thus plate 102 will
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be moved in the direction of arrow 103 which wlll move the end 104
of the plate 100 also outwardly a distance A or 0.1016mm from plate
102 by a thrust on the screw 68a. Thus, through diagonal corners
of the plate, the plate 100 will be moved outwardly for a clearance
of the column. This same action or relative movement occurs on the
plate 105 which is opposite the plate 100, and likewise the same
action will occur on the other opposite plates 106 and 102. Thus,
all four plates not only move outwardly away ~rom the column a
distance B or .01778mm but also endwise a distance A or .1016mm at
the same time that the pressure is applied which causes the flexing
of the screws 68 as indicated in Fig. 9.
The slide carries a probe 85 (Fig. 6) on an arm 86 attached to
the slide as at 87 and which is on the end of a laterally extending
arm 88. This probe designated generally 85 is generally triangular
in shape with the pointed end 89 suitable for indicating on the work
the position of the gage. Different shape probes may be provided
rigidly attached to the slide. The probe 85 is in the form of a
sllce of a cone containing its center axis with the upper surface 90
and lower surface 91 of the probe on the arc of the same circle so
that when the probe extends into an opening, a single point on the
same circle on each surface 90 and 91 will engage the opening to
locate the center of a diameter.
Pins 95 extend laterally from the triangular probe and are lo-
cated with the lower surface on the center line of the probe. The
probe may be set by means of a calibrating block 96 which will rest
upon a flat surface 97 and a probe may be level, and then the cali-
brating block 96 may be turned around 180 about a vertical axis to
see if the pins 95 engage the calibrat~ng block 96, and when this
condition of touching with the calibrating block reversed through
180, the probe will be in the proper aligned position.
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