GB1583893A

GB1583893A - Gauging devices for use in determining whether two cylindrical surfaces are coaxially aligned

Info

Publication number: GB1583893A
Application number: GB2534977A
Authority: GB
Original assignee: USM Corp
Current assignee: USM Corp
Priority date: 1976-06-18
Filing date: 1977-06-17
Publication date: 1981-02-04
Also published as: IT1115490B; DE2727062A1; BR7703987A; FR2354838B1; FR2354838A1; JPS52156492A; CA1051232A; JPS6121761B2; CH620990A5; MX144424A

Abstract

A first sensing device (20) has a bow (25) which can be swivelled about a bolt (32) and has two sensor elements (26, 27) which are intended for bearing against a cylindrical surface, which is approximately parallel to the bolt (32), at two points which are situated remote from one another on a circumference of the surface. The position of the axis of the cylindrical surface, measured in the direction of a first coordinate axis approximately parallel to the straight line connecting the bearing points, determines the pivoting position of the bow (25), which is indicated by a first gauge (24). A second sensing device has a sensor (21) which can be displaced linearly in the direction of a second coordinate axis which is approximately perpendicular to the first coordinate axis and to the bolt (32). The position of the axis of the cylindrical surface measured in the direction of the second coordinate axis is indicated by a second gauge (22), which is actuated by this sensor (21). The measuring device serves, when mounted displaceably on a lathe parallel to the spindle axis, for aligning a workpiece axis coaxially with the spindle axis by comparing the gauge readings in the case of contact with a face plate fixed to the spindle and with the workpiece. <IMAGE>

Description

(54) IMPROVEMENTS IN OR RELATING TO GAUGING DEVICES FOR USE IN DETERMINING WHETHER TWO CYLINDRICAL SURFACES ARE COAXIALLY ALIGNED (71) We, USM CORPORATION, of Flemington, New Jersey, United States of America, a corporation duly organised under the laws of said State of New Jersey, having a place of business at 140 Federal Street, Boston, Commonwealth of Massachusetts, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention is concerned with improvements in or relating to gauging devices for use in determining whether two cylindrical surfaces are coaxially aligned. The invention finds application in, for example, the mounting of cylindrical workpieces in machine tools.

In normal operation of a lathe, a workpiece is mounted on the lathe for rotation about a machine axis (which can be referred to as a turning axis) and a tool is moved into engagement with the workpiece, while the workpiece is rotated, to remove material from the workpieces; the workpiece is accordingly machined to a cylindrical shape, with the cylinder axis coaxial with the turning axis of the lathe. Usually the tool is mounted on a carriage which enables it to be moved both radially of and parallel to the turning axis.

Sometimes it is required that a workpiece be machined on a lathe with the workpiece rotating about a predetermined axis of the workpiece. For this it is necessary that the workpiece be mounted on the lathe with the workpiece axis and the turning axis of the lathe coaxial. This requirement often arises where the predetermined axis is the cylinder axis of a previously formed cylindrical surface of the workpiece. Where the lathe, on which the workpiece is to be machined, comprises a faceplate with a cylindrical surface, of which the cylinder axis is coaxial with the turning axis of the lathe, the positioning of the workpiece on the lathe can be checked by determining whether the cylindrical surfaces of the workpieces and the faceplate are coaxially aligned. It is known to check whether the cylindrical surface of the workpiece is coaxial with the turning axis of the lathe by causing relative rotation about the turning axis between the workpiece and a deflection gauge which is mounted on the lathe at a fixed radius from the turning axis with a sensor of the gauge in contact with the cylindrical surface of the workpiece; during rotation, any eccentricity between the cylinder axis of the workpiece and the turning axis of the lathe will cause a defletion of the gauge. However, this and other known methods of setting the workpiece can be tedious and timeconsuming.

It is an object of the present invention to provide an improved gauging device for use in determining whether two cylindrical surfaces are coaxially aligned.

There is hereinafter described in detail, to illustrate the present invention by way of example, an illustrative machine which is a roll turning lathe and comprises an illustrative gauging device for use in determining whether two cylindrical surfaces are coaxially aligned. The illustrative gauging device comprises first sensing means for detecting a misalignment of the axis of a first cylindrical surface as measured along a first of two mutually orthongonal axes orthogonal to and intersecting the axis of the second cylindrical surface, and second sensing means for detecting a misalignment of the axis of the first cylindrical surface as measured along the second of the two mutually orthogonal axes.

The first sensing means of the illustrative device comprises a first sensor of the device, in the form of an arm constructed to make contact with a cylindrical surface at two points which are spaced-apart around the surface, and a first deflection indicator.

The first sensor is mounted for pivotal movement about a pivot axis parallel to the axis of the second cylindrical surface, the two points moving in a plane perpendicular to the pivot axis. The first sensor comprises first and second portions located to one side of the pivot axis and arranged to make contact with a cylindrical surface at two points as aforementioned, and a third portion located to the other side of the pivot axis and in contact with the first deflection indicator; the indicator is arranged to indicate pivotal movement of the first sensor about the pivot axis. Each of the first and second portions of the first sensor comprises a roller by which a cylindrical surface is contacted. The first sensor is mounted also for linear movement on the device along a path perpendicular to the pivot axis, towards and away from a cylindrical surface to be contacted, and the device comprises biasing means, in the form of a spring, urging the first sensor for linear movement in a direction towards a cylindrical surface to be contacted.

The second sensing means of the illustrative device comprises a linearly displaceable second sensor of the device, and a second deflection indicator of the device arranged to indicate linear displacement of the second sensor. The second sensor is a plunger arranged for displacement along a path parallel to the direction of linear movement of the first sensor perpendicular to the pivot axis of the first sensor, to operate the second indicator.

The illustrative machine is a machine for rotating a cylindrical workpiece about a machine axis (i.e. a turning axis of the lath), the machine comprising a reference member, provided by a faceplate of the lathe, with a cylindrical surface of which the cylinder axis is coaxial with the machine axis.

The machine also comprises workpiece supporting means on which a cylindrical workpiece can be mounted for rotation about the machine axis. The illustrative gauging device is secured on a tool slide of a tool carriage of the machine, in such a manner that it can be readily mounted and dismounted from the slide. The gauging device is thus mounted for movement on the machine along a path parallel to the machine axis, between a position in which the sensors of the device can make contact with the cylindrical surface of the faceplate (the faceplate providing the second cylindrical surface), and a position in which they can make contact with a cylindrical surface of a workpiece (providing the first cylindrical surface) mounted on the workpiece supporting means, so that the device can be used to determine whether the cylindrical surfaces of the faceplate and the workpiece are coaxially aligned. The tool slide, and thus the illustrative gauging device mounted thereon, is arranged for movement on the machine also along a path perpendicular to the machine axis. The gauging device is mounted on the tool slide so that the path in which the first sensor is pivotally moveable is perpendicular to the machine axis, and the direction of linear movement of the first sensor is parallel to the path of movement of the tool slide perpendicular to the machine axis. The second sensor is accordingly mounted for linear displacement along a path parallel to the path of movement of the tool slide perpendicular to the machine axis, the linear displacement of the second sensor being radially of the faceplate when the sensors are in contact with the cylindrical surface of the faceplate.

In use of the illustrative gauging device, the device is firstly positioned so that the two sensors are in contact with the cylindrical surface of the faceplate and the first and second indicators are set to give datum readings. The gauging device is then moved on the tool carriage parallel to the machine axis until opposite a cylindrical surface of a workpiece mounted on the lathe. The gauging device is then moved on the tool slide towards the turning axis a distance equal to the difference in radii of the cylindrical surfaces of the faceplate and the workpiece, to bring the two sensors into contact with the surface of the workpiece. Deflections (from the datum positions) indicated on the two indicators, indicate misalignment of the workpiece cylinder axis from the faceplace cylinder axis along each of two mutually orthogonal axes which intersect on the machine axis, and the position of the workpiece on the lathe can be adjusted (as hereinafter described) to reduce the deflections indicated to zero and so to align the workpiece cylinder axis coaxially with the machine axis of the lathe.

The inventlion provides a gauging device for use in determining whether two cylindrical surfaces are coaxially aligned, the device comprising first sensing means for detecting a misalignment of the axis of a first cylindrical surface as measured along a first of two mutually orthogonal axes orthogonal to and intersecting the axis of the second cylindrical surface, and second sensing means for detecting a misalignment of the axis of the first cylindrical surface as measured along the second of said two mutually orthogonal axes, said first sensing means comprising a first sensor of the device constructed to make contact with a cylindrical surface at two points which are spaced apart around the surface and mounted for pivotal movement about an axis parallel to the axis of the second cylindrical surface, and a first deflection indicator of the device arranged to indicate pivotal movement of the first sensor, and said second sensing means comprising a displaceable second sensor of the device, and a second deflection indicator of the device arranged to indicate displacement of the second sensor.

The invention also provides a machine for rotating a cylindrical workpiece about a machine axis, the machine comprising a reference member with a cylindrical surface of which the cylinder axis is coaxial with the machine axis, workpiece supporting means on which a cylindrical workpiece can be mounted for rotation about the machine axis, and a gauging device as set out in the last preceding paragraph, the gauging device being mounted for movement on the machine along a path parallel to the machine axis between a position in which the two sensors of the device can make contact with the cylindrical surface of the reference member and a position in which the two sensors of the device can make contact with the cylindrical surface of a workpiece mounted on the workpiece supporting means, so that the device can be used to determine whether the cylindrical surfaces of the reference member and the workpiece are coaxially aligned.

There now follows a detailed description, to be read with reference to the accompanying drawings, of the illustrative machine and the illustrative gauging device aforementioned. It is to be understood that this illustrative machine and this illustrative gauging device have been selected for description to illustrate the invention by way of example and not by way of limitation.

In the accompanying drawings: Figure 1 is a perspective view of the illustrative machine; Figure 2 is a perspective view of a tool slide of the illustrative machine with a cutting tool mounted on the slide in place of the illustrative gauging device; Figure 3 is a side view of the illustrative gauging device engaging a cylindrical surface; Figure 4 is a front view of the illustrative device; Figure 5 is a plan view from above of the illustrative device; Figure 6 is a perspective view of the illustrative device engaging a cylindrical surface; and Figure 7 is a chart diagramatically illustrating use of the illustrative device.

The illustrative machine, being a roll turning lathe, is shown in Figure 1. The machine comprises a head stock 1 and a tail stock 2. The head stock 1 and the tail stock 2 have faceplates 4 and 5 respectively, mounted thereon for rotation about a machine axis referred to hereinafter as the turning axis 3. The faceplates 4, 5 provide cylindrical surfaces of which the cylinder axes are coaxial with the turning axis 3.

A workpiece in the form of a roll 6 is shown in Figure 1 mounted between the head stock 1 and the tail stock 2, and com prises journals 7 and 8 which have cylin drical surfaces of which the cylinder axes are coaxial with the desired axis of the roll 6. The roll 6 is supported on workpiece supporting means comprising steady rests 9 and 10.

As shown in Figure 2, a tool 11 can be mounted on a tool block 12 of the illustrative machine, the block 12 being releasably secured to a tool slide 13. The tool slide 13 provides for manual adjustment of the position of the tool 11 in a horizontal direction perpendicular to the turning axis 3.

The tool slide 13 is mounted in a cross slide 14 which further provides for transverse adjustment of the tool position. The assembly of the tool 11, the tool block 12, the tool slide 13 and the cross slide 14 is mounted on a tool carriage 15 which is mounted for movement, parallel to the turning axis 3, along a rail 16. Movement of the cross slide 14 and the tool carriage 15 can be automatically controlled from an electronic control unit 17 mounted on the carriage 15.

As shown in Figure 2, the tool block 12 is releasably secured to the tool slide 13 by means of a cylindrical cam 18 mounted for rotation on the tool slide 13. The shape of the cam is such as to engage the tool block 12 and rigidly secure it in a required position. The illustrative gauging device of the illustrative machine is mounted, as shown in Figures 3 and 6, in place of the tool 11 and tool block 12 on the tool slide 13.

The illustrative gauging device, shown in Figures 3 to 6, is a device for use in determining whether two cylindrical surfaces are coaxially alinged. The illustrative gauging device comprises first sensing means 20 for detecting a misalignment of the axis of a first cylindrical surface as measured along a first of two mutually orthogonal axes orthogonal to and intersecting the axis of the second cylindrical surface (in the illustrative machine, the surface of one of the faceplates 4, 5), and second sensing means 19 for detecting a misalignment of the axis of the first cylindrical surface as measured along the second of the two mutually orthogonal axes. As employed on the illustrative machine, the first of the two mutually orthogonal axes is vertical and the second horizontal, the two axes extending radially of the turning axis 3.

The illustrative gauging device comprises a supporting block 23 which is mounted on the tool slide 13 in place of the tool block 12. The first sensing means 20 of the device comprises a first sensor of the device constructed to make contact with a cylindrical surface at two points which are spacedapart around the surface. The first sensor comprises an arm 25 mounted for pivotal movement in a path perpendicular to the turning axis 3 of the machine; the arm 25 is mounted on a bolt 32 to pivot about a pivot axis perpendicular to the plane in which the arm is movable, i.e. parallel to the turning axis 3. The arm 25 is generally Y-shaped, with first and second portions located to one side of the pivot axis and arranged to make contact with a cylindrical surface at two points which are spaced-apart around the surface, each of the first and second portions comprising a roller 26, 27 by which the surface is contacted. The first sensing means 20 comprises also a first deflection indicator of the device, in the form of a deflection gauge 24, arranged to indicate pivotal movement of the arm 25. As shown in Figure 3, an operating plunger 29 for the gauge 24 is in engagement with a stem 30 of the arm 25; the stem 30 thus provides a third portion of the first sensor, located to the other side of the pivot axis from the first and second portions, in contact with the first deflection indicator. The arm 25 and gauge 24 are together mounted by way of a ball slide 28 on the supporting block 23, the ball slide 28 permitting linear movement of the arm 25 along a path perpendicular to the turning axis 3 (and thus of the pivot axis of the arm 25); the arm 25 is resliently urged by a spring 33 along the path in a direction towards a cylindrical surface to be contacted (i.e. from right to left, as shown in Figure 3).

The second sensing means 19 of the illustrative device comprises a linearly displaceable second sensor of the device, and a second deflection indicator of the device arranged to indicate linear displacement of the second sensor. The second seonsor is arranged for displacement along a path parallel to the path of linear movement of the arm 25, perpendicular to the turning axis 3 (and thus the pivot axis of the arm 25). The second sensor comprises an operating plunger 21 of the second deflection indicator, which is a deflection gauge 22 mounted on the supporting block 23 of the illustrative gauging device.

Use of the illustrative gauging device will now be described. The illustrative machine is a machine for rotating a cylindrical workpiece (i.e. the roll 6) about a machine axis (i.e. the turning axis 3) one of the journals 7, 8 of the roll 6 providing a first cylindrical surface. The machine comprises a reference member with a cylindrical surface of which the cylinder axis is coaxial with the machine axis, provided by either one of the two faceplates 4, 5, the reference member providing a second cylindrical surface. The machine also comprises workpiece supporting means (i.e. comprising the steady rests 9, 10) on which a cylindrical workpiece can be mounted for rotation about the turning axis, and the illustrative gauging device. The gauging device, being mounted on the tool slide 13 on the tool carriage 15, is mounted for movement on the machine along a path parallel to the turning axis between a position in which the sensors (i.e. the rollers 26, 27 on the arm 25 of the first sensor and the operating plunger 21 of the second sensor) can make contact with the cylindrical surface of the reference member (e.g. the faceplate 5), and a position in which the sensors can make contact with the cylindrical surface (e.g. that of the journal 8 of the roll 6, as shown in Figure 6) of a workpiece mounted on the workpiece supporting means, so that the illustrative gauging device can be used to determine whether the cylindrical surfaces of the reference member and the workpiece are coaxially aligned. On the tool slide 13, the gauging device is mounted for movement on the machine also along a path perpendicular to the machine axis, and parallel to the direction in which the operating plunger 21 of the second sensor is linearly displaceable. The gauging device is mounted so that when the sensors are in contact with the cylindrical surface of the reference member (i.e. the faceplate 5) the operating plunger 21 of the second sensor is linearly displaceable radially of the reference member.

In Figure 7, axial misalignment of the cylindrical surfaces of the faceplate 5 and the journal 8 is diagrammatically illustrated.

The illustrative gauging device is first moved to a position in which the rollers 26, 27 on the arm 25 and the operating plunger 21 of the gauge 22 are in engagement with the cylindrical surface of the faceplate 5. Adjustable scales of the two deflection gauges 22, 24 are zeroed. The gauging device is then moved, by means of the tool carriage 15, along the machine to a position opposite the surface of the journal 8. The gauging device is then moved, by means of the cross slide 14 and the tool slide 13, towards the turning axis 3 (the journal 8 being of smaller diameter than the faceplate 5) until the gauging device is in a position closer to the turning axis 3, than it had been when the deflection gauge scales were zeroed, by a distance (rl-r2) equal to the difference in the radii of the faceplate 5 and the journal 8; if the journal 8 and the faceplate 5 were coincident at the position in which the gauging device is located, the deflection gauges 22, 24 would now both indicate zero deflection.

The first sensing means of the illustrative device detects misalignment of the cylinder axes as measured along an axis Y in Figure 7 (misalignment dY), and the second sensing means detects misalignment of the cylinder axes as measured along an axis X (misalignment dX). As shown diagramatically in Figure 7, the misalignment dY causes the arm 25 to be pivoted through an angle G, which results in a deflection of the stem 30 of the arm being indicated by the gauge 24.

The position of the roll 6 is vertically adjusted until the deflection indicated on the gauge 24 is zero (and accordingly the angle G is zero); in this condition the cylinder axis of the journal 8 is coincident with the turning axis 3 (i.e. the cylinder axis of the faceplate 5) as measured along the axis Y. When the roll 6 has been so adjusted to reduce the error dY to zero, the position of the roll can be adjusted horizontally until the deflection indicated on the gauge 22 is zero; in this condition the cylinder axis of the journal 8 is coincident with the turning axis 3 as measured along the axis X, the error dX having been reduced to zero. When both of the gauges 22, 24 indicate zero deflection it is known that, at the position in which the gauging device is located, the desired axis of the roll 6 is coincident with the turning axis 3 of the machine. To ensure accuracy, the guaging device can then be moved into engagement with the other journal 7 to check the coincidence of the axes also at the journal 7 and any necessary adjustments made. When the axis of the roll 6 and turning axis 3 are established to be coincident at both journals 7, 8 the roll 6 is coaxially aligned with the turning axis 3. In this way, by use of the illustrative gauging device, the roll 6 can be set in the machine so as to be turned on operation of the machine about the desired axis, being the cylinder axis of the coaxial journals 7, 8.

WHAT WE CLAIM IS: 1. A gauging device for use in determining whether two cylindrical surfaces are coaxially aligned, the device comprising first sensing means for detecting a misalignment of the axis of a first cylindrical surface as measured along a first of two mutually orthogonal axes orthogonal to and intersecting the axis of the second cylindrical surface, and second sensing means for detecting a misalignment of the axis of the first cylindrical surface as measured along the second of said two mutually orthogonal axes, said first sensing means comprising a first sensor of the device contructed to make contact with a cylindrical surface at two points which are spaced apart around the surface and mounted for pivotal movement about an axis parallel to the axis of the second cylindrical surface, and a first deflection indicator of the device arranged to indicate pivotal movement of the first sensor, and said second sensing means comprising a dis placeable second sensor of the device, and a second deflection indicator of the device arranged to indicate displacement of the second sensor.

2. A gauging device according to claim 1 in which the first sensor comprises first and second portions located to one side of the pivot axis and arranged to make contact with a cylindrical surface at two points which are spaced-apart around the surface, and a third portion located to the other side of the pivot axis and in contact with said first deflection indicator.

3. A gauging device according to claim 2 in which each of said first and second portions comprises a roller by which a cylindrical surface is contacted.

4. A gauging device according to one of claims 1, 2 and 3 in which the first sensor is mounted also for linear movement on the device, towards and away from a cylindrical surface to be contacted.

5. A gauging device according to claim 4 comprising biasing means resiliently urging the first sensor for linear movement in a direction towards a cylindrical surface to be contacted.

6. A gauging device according to either one of claims 4 and 5 in which said first sensor is mounted for linear movement along a path perpendicular to the pivot axis.

7. A gauging device according to any one of the preceding claims in which said second sensor is mounted for linear displacement.

8. A gauging device according to claim 7 in which the first sensor is mounted also for linear movement towards and away from a cylindrical surface to be contacted, said second sensor being mounted for linear displacement along a path parallel to the direction of linear movement of the first sensor.

9. A gauging device according to either one of claims 7 and 8 in which said sensor is mounted for linear displacement along a path perpendicular to the pivot axis of the first sensor.

10. A gauging device constructed arranged and adapted to operate substantially as the illustrative gauging devices hereinbefore described with reference to the accompanying drawings.

11. A machine for rotating a cylindrical workpiece about a machine axis, the machine comprising a reference member with a cylindrical surface of which the cylinder axis is coaxial with the machine axis, workpiece supporting means on which a cylindrical workpiece can be mounted for rotation about the machine axis, and a gauging device according to any one of claims 1 to 10, the gauging device being mounted for movement on the machine along a path parallel to the machine axis between a posi tion in which the two sensors of the device can make contact with the cylindrical sur face of the reference member and a position in which the two sensors of the device can make contact with the cylindrical surface of a workpiece mounted on the workpiece sup porting means, so that the device can be used to determine whether the cylindrical surfaces of the reference member and the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. gauge 24 is zero (and accordingly the angle G is zero); in this condition the cylinder axis of the journal 8 is coincident with the turning axis 3 (i.e. the cylinder axis of the faceplate 5) as measured along the axis Y. When the roll 6 has been so adjusted to reduce the error dY to zero, the position of the roll can be adjusted horizontally until the deflection indicated on the gauge 22 is zero; in this condition the cylinder axis of the journal 8 is coincident with the turning axis 3 as measured along the axis X, the error dX having been reduced to zero. When both of the gauges 22, 24 indicate zero deflection it is known that, at the position in which the gauging device is located, the desired axis of the roll 6 is coincident with the turning axis 3 of the machine. To ensure accuracy, the guaging device can then be moved into engagement with the other journal 7 to check the coincidence of the axes also at the journal 7 and any necessary adjustments made. When the axis of the roll 6 and turning axis 3 are established to be coincident at both journals 7, 8 the roll 6 is coaxially aligned with the turning axis 3. In this way, by use of the illustrative gauging device, the roll 6 can be set in the machine so as to be turned on operation of the machine about the desired axis, being the cylinder axis of the coaxial journals 7, 8. WHAT WE CLAIM IS:

1. A gauging device for use in determining whether two cylindrical surfaces are coaxially aligned, the device comprising first sensing means for detecting a misalignment of the axis of a first cylindrical surface as measured along a first of two mutually orthogonal axes orthogonal to and intersecting the axis of the second cylindrical surface, and second sensing means for detecting a misalignment of the axis of the first cylindrical surface as measured along the second of said two mutually orthogonal axes, said first sensing means comprising a first sensor of the device contructed to make contact with a cylindrical surface at two points which are spaced apart around the surface and mounted for pivotal movement about an axis parallel to the axis of the second cylindrical surface, and a first deflection indicator of the device arranged to indicate pivotal movement of the first sensor, and said second sensing means comprising a dis placeable second sensor of the device, and a second deflection indicator of the device arranged to indicate displacement of the second sensor.

workpiece are coaxially aligned.

12. A machine according to claim 11 in which the gauging device is mounted for movement on the machine also along a path perpendicular to the machine axis.

13. A machine according to either one of claims 11 and 12 in which the path in which the first sensor is pivotally moveable is perpendicular to the machine axis.

14. A machine according to claim 12 in which the first sensor is mounted also for linear movement towards and away from a cylindrical surface to be contacted, the direction of linear movement of the first sensor being parallel to said path perpendicular to the machine axis.

15. A machine according to claim 12 in which the second sensor is mounted for linear displacement along a path parallel to said path perpendicular to the machine axis, the displacement of the second sensor being radially of the machine axis when the sensors are in contact with the cylindrical surface of the reference member.

16. A machine constructed arranged and adapted to operate substantially as the illutrative machine hereinbefore described with reference to the accompanying drawings.