US3452483A

US3452483A - Grinding machines

Info

Publication number: US3452483A
Application number: US596326A
Authority: US
Inventors: Keith Trevor Lambert; Stanley Prior
Original assignee: James A Jobling and Co Ltd
Current assignee: James A Jobling and Co Ltd
Priority date: 1965-11-29
Filing date: 1966-11-22
Publication date: 1969-07-01
Anticipated expiration: 1986-07-01
Also published as: FR1503061A; GB1093167A; ES333666A1

Description

July 1, 1969 K. T. LAMBERT ETAL GRINDING MACHINES Sheet Filed Nov. 22, 1966 July 1, 1969 K. T. LAMBERT ETAL GRINDING MACHINES Filed Nov. 22, 1966 Shaer. ,8 of 2 FIG. 2-

United States Patent U.S. Cl. 51-55 10 Claims ABSTRACT OF THE DISCLOSURE A machine for grinding flat the ends of glass tubes includes a rotatably-driven grinding wheel having a flat grinding face disposed in a plane perpendicular to the axis of rotation. During operation the grinding wheel swings pendulum-fashion in said plane.

This invention relates to grinding machines and is in particular, although not exclusively, concerned with machines for grinding the ends of elongated articles such as glass tubes.

According to the present invention there is provided a grinding machine comprising a grinding member supported for swinging with its grinding face disposed in an upright plane, means for imparting swinging motion to the grinding member, and means for supporting a Workpiece such that a surface of the workpiece can be moved into said plane to be ground by the grinding member during said swinging motion thereof.

For a better understanding of the invention and to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings, in which:

FIGURE 1 is a diagrammatic side view of the grinding machine,

FIGURE 2 is a diagrammatic end view of the machine of FIGURE I viewed in the direction of arrow II of FIG- URE 1, and

FIGURE 3 is a diagrammatic end view, on a larger scale, of a part of the machine of FIGURES 1 and 2 viewed in the same direction as FIGURE 2 and illustrating operation of the machine.

The machine is shown in FIGURES 1 and 2 set-up for; grinding the ends of a glass tube 1 flat and parallel with one another. The machine has an elongated horizontal bed 2 on a flat slideway 2A of which are adjustably mounted for movement along the slideway two work rests 3 each carrying a pair of rollers 4 for supporting a workpiece (in the case illustrated the glass tube 1). The rollers 4 are of a synthetic plastic material such as nylon.

At one end of the machine, the machine bed 1 carries an upright bracket '5 to the top of which is secured a motor 6. Adjacent the bracket 5 the end portion of the machine bed 1 carries two spaced apart yoke-like brackets 7 which rigidly support, above the bed 1, a shaft -8 extending longitudinally and centrally of the bed 1 and coaxially with the shaft of the motor 6. A swinging arm 9 depends from the shaft 8 between the brackets 7, bearings 10 housed in the upper portion of the arm 9 co-operating with the shaft 8. Further bearings 11 housed in the bottom portion of the swinging arm 9 rotatably support a shaft 12 so that it extends longitudinally of the bed 1 and centrally thereof when the arm 9 is hanging normally.

Each end of the shaft 12 projects from the arm 9 and the projecting end remote from the motor support bracket 5 carries a grinding wheel 13. The wheel 13 is supported with its grinding face 13A perpendicular to the plane of the upper surface of the slideway 2A. The wheel 13 may be, for example, a silicone carbide bonded wheel, or it may be a cast iron wheel. In a case such as the former pipes (not shown) for continuously supplying water to the wheel 13, during grinding, are provided whilst in a case such as the latter a continuous feed of silicone carbide slurry is fed to the wheel 13 during operation.

The projecting end of the shaft 12 that is adjacent the motor support bracket 5 passes through bearings carried by a support bracket 14 secured to the arm 9 and a pulley or sprocket wheel 15 is mounted on this end of the shaft 12. The pulley or sprocket wheel 15 is below a similar pulley or sprocket wheel 16 on the shaft of the motor 6 and an endless V-belt or chain 17 runs around the two pulleys or

wheels

15, 16 so that the motor 6 may drive the shaft 12 and therefore the grinding wheel 13.

A bracket 18 (FIGURE 2) extending horizontally from one side of the machine bed 1 carries trunnions 19, at its end remote from the bed 1, that pivotally support one end of an air cylinder 20. The rod 21 of a piston in this air cylinder 20 is pivotally connected to a lug 22 on the arm 9. The axis of the air cylinder 20 is transverse to the longitudinal axis of the machine bed 1. A suitable pneumatic circuit (not shown) is provided for causing the piston in the cylinder 20 to reciprocate whereby swinging motion is imparted to the arm 9. The stroke of the piston can be selected in accordance with the length of the are it is desired the arm 9 should swing through. It will be appreciated that the disposition of the shafts 8 and 12 is such that the grinding face 13A of the wheel 13 swings in a plane that is at right-angle to the plane of the upper sur face of the slideway 2A.

The operation of the grinding machine shown in the figures will now be described with reference to the grinding of the ends of an elongated workpiece such as the glass tube 1 shown in the figures. To set-up the machine the work rests 3 are positioned on the bed 1 so that one set of the rollers 4 is about 3 inches from the grinding wheel 13 whilst the other set of rollers 4 support the tube 1 at about 3 inches from its end remote from the wheel 13, the work rests 3 being set so that the axes of the rollers 4 lie in the same horizontal plane. The stroke of the piston in the air cylinder 20 is set to cause the swinging motion imparted to the arm 9 to be such that throughout most of its movement the wheel 13 entirely covers the end of the tube 1 when the tube is resting on the rollers 4 with this end against the Wheel 13, but such that at the end of this movement in one direction a part of the end of the tube 1 is clear of the wheel 13. In this connection, it will be noted from the figures that the disposition of the work rests 3 and the rollers 4 is such that the tube 1 is supported offset from, but parallel with, the longitudinal axis of the machine bed, the longitudinal axis of the tube 1 extending normally to the plane in which the face 13A swings. Thus the workpiece is supported so as to be displaced from the central point of the are through which the grinding wheel swings durin operation of the machine.

With the machine set-up as described, the motor 6 and the piston in the cylinder 20 are set in operation respectively to rotate the grinding wheel 13 and to cause the arm 9 to swing, and the tube 1 is placed on the rollers and pushed, by hand, into contact with the rotating, swinging, grinding wheel 13. Feeding of the tube 1 to the grinding wheel 13 is continued manually and, at the same time, the tube is manually rotated on the rollers 4. When grinding of one end of the tube has been completed, the tube is turned around and the other end ground in the same way. It will be appreciated that, due to the construction of the machine, this end will be ground parallel to the end first ground. In actual practice it has been possible to obtain parallelism of the two ends of a glass 3 tube such as the tube 1 to within .004 inch, the ends being ground to a flatness of within .002 inch.

If a somewhat misshapen, or even square, tube has to be ground, round clamps are secured to the tube to rest on the rollers 4. The fixing of such clamps to the tube enables the tube to be rotated on the rollers 4 without the outside configuration of the tube affecting this rolling operation.

It will be appreciated that, although manual feeding of an elongated circular glass tube resting freely on the work rests has been described, the machine can be provided with jigs and/or a mechanical feed arrangement to enable the ends of more intricately shaped articles to be ground, for example, T-pieces, cross-pieces and tubes of hexagonal and octagonal section. Also the machine is not, of course, restricted to the grinding of glass articles.

We claim:

1. A grinding machine comprising a grinding member, a planar grinding face on the grinding member, means supporting the grinding member for swinging with its grinding face continually disposed in an upright plane,

means for imparting swinging motion to the grinding member, and means for supporting a workpiece such that a surface of the workpiece can be moved into said plane to be ground by the grinding face of the grinding member during said swinging motion thereof.

2. A grinding machine according to claim 1, wherein the means supporting the grinding member is a swingable arm, and wherein the grinding member is a grinding wheel that is rotatably supported in said swingable arm, the machine further comprising means for rotating the wheel during said swinging motion thereof.

3. A grinding machine according to claim 2, wherein the last-mentioned means includes a motor and an endless transmissionmeans for transmitting drive from the motor to the grinding wheel.

4. A grinding machine according to claim 2, wherein the means for imparting swinging motion to the grinding member comprises a trunnion-mounted piston and cylinder arrangement pivotally connected to said arm.

5. A grinding machine according to claim 4, wherein the operational stroke of the piston and cylinder arrangement is adjustable.

6. A grinding machine according to claim 1, wherein the workpiece supporting means includes an elongated horizontal slideway and work-rests adjustably mounted on the slideway for supporting an elongated workpiece such that its longitudinal axis extends normal to said plane.

7. A grinding machine according to claim 6, wherein said work-rests are mounted on the slideway so as to support an elongated workpiece displaced from the central point of the are through which the grinding member swings during operation of the machine.

8. A grinding machine for grinding a surface of a workpiece to produce a fiat surface comprising a rotatably driven grinding wheel having a flat grinding face disposed in a plane which is perpendicular to the axis of rotation of said grinding wheel; means supporting said grinding wheel for arcuate swinging movement such that said grinding face swings in said plane; means for imparting reciprocating swinging movement to said grinding wheel during rotation thereof; and means for supporting a workpiece and for moving the same into but not through said plane and into grinding engagement with said rotating and swinging grinding face.

9. A grinding machine as in claim 8 wherein said workpiece support means is disposed to move the workpiece into said plane near one end of the arcuate path of travel of said grinding wheel whereby part of the workpiece surface being ground may be clear of said grinding face at said end of the arcuate path of travel of said grinding wheel.

10. A method for grinding the end of an elongated workpiece to produce a flat surface comprising: rotating about its own axis a grinding wheel having a fiat grinding face disposed in a plane perpendicular to the axis of rotation; moving said workpiece so as to engage said end with said rotating grinding face; and swinging said grinding wheel in said plane while said end of said workpiece is in engagement with said grinding face.

References Cited JAMES L. JONES, JR., Primary Examiner.

US. Cl. X.R. 51-99, 125, 289