Position indicator for machine tools

Claim 2

Apparatus for indicating the position of a member movable in response to a bidirectionally rotatable drive mechanism, comprising: a resettable counter for providing a coarse, digital indication of accumulated displacement of the member in either direction from a zero point; a transmission coupled to be driven by the drive mechanism, the transmission having a first output movable in a given direction when the drive mechanism is rotated clockwise and a second output movable in said given direction when the drive mechanism is rotated counterclockwise; clutch means coupling said counter and transmission and selectively movable to engage one or the other of the transmission outputs to advance the counter during rotation of the drive mechanism; a first, rotatable dial coupled to the drive mechanism for rotation therewith, said first element having a peripheral surface provided with circumferentially spaced reference markings; a second dial having a peripheral surface disposed adjacent the peripheral surface of the first dial and provided with a bidirectional vernier scale; and means for manually controlling the position of the second dial whereby the markings on the surface of the second dial may be brought into aligNment with the markings on the surface of the first dial.

Claim 3

Apparatus, as defined in claim 1, in which said transmission outputs comprise a pair of contrarotatable gears, each gear having a surface adapted to be frictionally engaged by the clutch means.

Claim 4

Apparatus, as defined in claim 2, in which: said output gears are mounted in face-to-face, coaxial relation and cupped to define a cylindrical chamber; and said clutch means includes: a disc-shaped piston coaxially disposed within the cylindrical chamber and mounted on a reciprocable drawbar means coupled to drive the counter, and means supported by the periphery of the piston for frictionally engaging the chamber wall of one or the other output gear in accordance with the selected position of the drawbar means, whereby motion is transmitted from one or the other output gear, through the frictional gear-engaging means and the piston to the drawbar means.

Claim 5

Apparatus, as defined in claim 1, which includes gear train means connecting the rotatable drive mechanism with the transmission and the first dial for converting displacement of the member in terms of the English measuring system to indications of displacement in metric units.

Claim 6

Apparatus, as defined in claim 4, in which said gear train means comprises first and second gear trains, the drive ratio of the first train providing indications in English units, the drive ratio of the second train providing indications in metric units, said apparatus further including clutch means cooperating with the gear trains and selectively operable to drive the transmission and first dial with either the first or second gear train.

Claim 7

In a machine tool having a bidirectional lead screw drive for displacing a table carrying the work piece to be formed, a table position indicator comprising: a resettable counter having four rotatable, decade number wheels for providing a coarse, digital indication of table displacement from an arbitrary zero point, the first number wheel being directly driven with a 1:1 ratio by a counter input gear, the remaining three number wheels being intermittently rotatable by a succession of geneva movements with 10:1 ratios; gear transmission means coupling the lead screw drive with the counter input gear, the transmission means including a dual gear train having a pair of contrarotating, abutting output gears coaxial with each and the counter input gear, both output gears being recessed from their abutting faces to define a cylindrical chamber; a clutch mechanism including: a disc-shaped piston disposed within the cylindrical chamber coaxially therewith, the piston having a circumferential groove, a generally ring-shaped spring seated within the groove and having one end connected to the piston to prevent rotation of the spring relative to the piston, and a free end which tends to move outwardly from the groove, said spring being restrained from outward expansion by the walls of the cylindrical chamber to provide a frictional coupling between the output gears and the piston, a drawbar, extending coaxially of the output gears, affixed to the piston and reciprocably mounted to axially position the piston and spring within the chamber to engage one or the other output gear, a spline, affixed to the drawbar and slidably engaged with the counter input gear, for transmitting rotational motion from the piston to the counter input gear, and manually actuable cam means, coupled to the drawbar, for reciprocating the drawbar, whereby the transmission output gear to drive the counter is selected; and a vernier indicator, comprising: a first dial, coupled to be driven by the lead screw and having a peripheral surface provided with reference markings including axially oriented lines spaced circumferentially about the peripheral surface at equal intervals, a second dial, concentric with the first dial, having a peripheral surface adjacent the peripheral surface of the first dial, the peripheral surface of the second dial being provided with a bidirectional vernier scale for cooperation with the reference markings on the first dial, and rack and pinion means for manually adjusting the angular position of the second dial.

Claim 8

In a machine tool having a bidirectional lead screw drive for displacing a table carrying the work piece to be formed, a table position indicator comprising: a resettable counter having four rotatable, decade number wheels for providing a coarse, digital indication of table displacement from an arbitrary zero point, the first number wheel being directly driven with a 1:1 ratio by a counter input gear, the remaining three number wheels being intermittently rotatable by a succession of geneva movements with 10:1 ratios; gear transmission means coupling the lead screw drive with the counter input gear, the transmission means including a dual gear train having a pair of contrarotating, abutting output gears coaxial with each and the counter input gear, both output gears being recessed from their abutting faces to define a cylindrical chamber; a clutch mechanism including: a disc-shaped piston disposed within the cylindrical chamber coaxially therewith, the piston having a circumferential groove, a generally ring-shaped spring seated within the groove and having one end connected to the piston to prevent rotation of the spring relative to the piston, and a free end which tends to move outwardly from the groove, said spring being restrained from outward expansion by the walls of the cylindrical chamber to provide a frictional coupling between the output gears and the piston, a drawbar, extending coaxially of the output gears, affixed to the piston and reciprocably mounted to axially position the piston and spring within the chamber to engage one or the other output gear, a spline, affixed to the drawbar and slidably engaged with the counter input gear, for transmitting rotational motion from the piston to the counter input gear, and manually actuable cam means, coupled to the drawbar, for reciprocating the drawbar, whereby the transmission output gear to drive the counter is selected; and a vernier indicator, comprising: a first dial, coupled to be driven by the lead screw and having a peripheral surface provided with reference markings including axially oriented lines spaced circumferentially about the peripheral surface at equal intervals, a second dial, concentric with the first dial, having a peripheral surface adjacent the peripheral surface of the first dial, the peripheral surface of the second dial being provided with a bidirectional vernier scale for cooperation with the reference markings on the first dial, and rack and pinion means for manually adjusting the angular position of the second dial.

Claim 9

A table position indicator, as defined in claim 6, in which said gear transmission means includes an English-to-metric conversion gear train coupling the lead screw with the dual gear train and the first dial, whereby the table position indicator reads in metric units.

Claim 10

Apparatus for accurately positioning a member connected to be displaced by a bidirectionally rotatable drive means, comprising: a first cylindrical member concentrically mounted on the drive means to rotate therewith and having an outer surface provided with a series of equally spaced, axially oriented reference lines; a second cylindrical member mounted coaxially of the first cylindrical member, the second member having an outer surface disposed immediately adjacent the outer surface of the first member and provided with a bidirectional vernier scale extending on each side of a zero line a distance equal to the distance between adjacent reference lines on the first member; and means for displacing the second member angularly between limits including an arcuate gear rack formed in the second member and a manually rotatable pinion means in mesh with the rack.

Claim 11

Apparatus for accurately positioning a member connected to be displaced by a bidirectionally rotatable drive means, comprising: a first cylindrical member concentrically mounted on the drive means to rotate therewith and having an outer surface provided with a series of equally spaced, axially oriented reference lines; a second cylindrical member mounted coaxially of the first cylindrical member, the second member having an outer surface disposed immediately adjacent the outer surface of the first member and provided with a bidirectional vernier scale extending on each side of a zero line a distance equal to the distance between adjacent reference lines on the first member; and means for displacing the second member angularly between limits including an arcuate gear rack formed in the second member and a manually rotatable pinion means in mesh with the rack.

Claim 12

Apparatus for indicating the displacement of a member bidirectionally movable in response to rotation of a drive means, including: a resettable counter for displaying the accumulated displacement of the member in either direction from a reference; gear train means coupled to the drive means and having counterrotatable outputs; coupling means, selectively operable to connect one or the other of the gear train outputs with the counter to advance the counter during rotation of the drive means; and vernier means for providing fine indications of displacement comprising: a first dial connected to be driven by the drive means and having an outer surface with a series of equally spaced markings, and a second dial having an outer surface disposed adjacent to the outer surface of the first dial and having a series of markings forming a vernier scale, said second dial being selectively positionable to permit alignment of the markings on the second dial with the markings on the first dial.

Claim 13

Apparatus for indicating the displacement of a member bidirectionally movable in response to rotation of a drive means, including: a resettable counter for displaying the accumulated displacement of the member in either direction from a reference; gear train means coupled to the drive means and having counterrotatable outputs; coupling means, selectively operable to connect one or the other of the gear train outputs with the counter to advance the counter during rotation of the drive means; and vernier means for providing fine indications of displacement comprising: a first dial connected to be driven by the drive means and having an outer surface with a series of equally spaced markings, and a second dial having an outer surface disposed adjacent to the outer surface of the first dial and having a series of markings forming a vernier scale, said second dial being selectively positionable to permit alignment of the markings on the second dial with the markings on the first dial.