US 4,899,628 A · Dynamically compensating counterbalance

Abstract

A dynamically compensating counterbalance enables a numerically controlled contouring head to maintain proper balance through large slide travels, cutting tool radial travels, and weight changes in the cutting tool at high speeds. A counterweight within the contouring head moves oppositely to the slide direction by means of a pair of interconnected fluid cylinders. Slide reciprocation under numerical control pumps the first cylinder to slave the second cylinder and the counterweight connected thereto. The counterweight is of a high density material, thereby enabling the counterweight to have lesser and proportional travel than the corresponding slide travel while maintaining proper counterbalance. Proportional slide and counterweight travels are accomplished by employing cylinders of an unequal areas. The invention includes a servo operated third cylinder in fluid communication with the first and second cylinders. The servo control senses certain imbalances and strokes the third cylinder to alter the fluid in the counterweight cylinder, thereby causing displacement of the counterweight without corresponding displacement of the slide, which remains under numerical control.

Claims44

Dependent claims

Counterbalanced rotary apparatus comprising:

a. a housing adapted to rotate about a central axis;
b. a slide retained in the housing for reciprocating toward and away from the central axis in a plane perpendicular thereto;
c. counterweight means reciprocatingly received within the housing and slide for reciprocation in the same general plane as the slide;
and
d. counterbalance means mounted solely within the housing for directly connecting the slide to the counterweight means and for being actuated directly by reciprocation of the slide to reciprocate the counterweight means in synchronization with and in the opposite direction as the slide to thereby provide balancing as the slide reciprocates toward and away from the central axis.

2 more elements

A contouring head for machining surfaces of revolution on a workpiece comprising:

a. a housing adapted to rotate about a central axis;
b. a slide received within the housing for rotation therewith and for reciprocation toward and away from the central axis in a plane perpendicular thereto, the slide including a cutting tool mounted thereon;
c. counterweight means received within the housing for rotation therewith and for reciprocation in the same general plane as the slide;
and
d. means interconnecting the slide and counterweight means for actuation by the slide for reciprocating the counterweight means in synchronization with and in opposite directions as the slide, wherein the means interconnecting the slide and counterweight means comprises first and second fluid cylinders, the first cylinder having a piston rod connected to the slide and the second cylinder having a piston rod connected to the counterweight means, the cylinders being in fluid communication with each other,
so that reciprocating the slide strokes the first cylinder piston rod to actuate the second cylinder piston rod and thereby reciprocate the counterweight means in synchronization with and in opposite directions to the slide.

3 more elements

In combination with a contouring machine having a headstock;

a sleeve rotatable in the headstock about a central axis;
and a spindle reciprocatingly received within the sleeve,
a contouring head for machining surfaces of revolution on a workpiece comprising:
a. a housing mounted to the sleeve for rotation therewith;
b. a slide received within the housing for reciprocating in a plane perpendicular to the central axis toward and away therefrom;
c. drive means between the slide and spindle for reciprocating the slide in response to reciprocation of the spindle;
d. counterweight means within the housing and at least partially received within the slide for reciprocating therein;
and
e. counterbalance means connecting the slide to the counterweight means for reciprocating the counterweight means in synchronization with an in opposite directions as the slide reciprocation, wherein the counterbalance means comprises:
i. at least one first fluid cylinder within the housing having a working piston end and a piston rod connected to the slide;
ii. at least one second fluid cylinder within the housing having a working piston end and a piston rod attached to the counterweight means;
and
iii. means for providing fluid communication between the respective piston ends of the first and second cylinders,
so that reciprocation of the slide produces corresponding motion of the first and second cylinder piston rods and the counterweight means.

11 more elements

In a machine for machining surfaces of revolution on a workpiece and having a headstock;

a flanged sleeve mounted for rotation about a central axis in the headstock;
a spindle mounted for reciprocation along the central axis within the sleeve;
and a first control means for reciprocating the spindle within the sleeve,
a dynamically compensated counterbalance comprising:
a. a housing mounted to the sleeve for rotation therewith;
b. a slide received within the housing for reciprocation toward and away from the central axis in a plane perpendicular thereto, the slide including a cutting tool adapted to machine the workpiece;
c. first drive means for reciprocating the slide in response to reciprocation of the spindle within the sleeve;
d. counterweight means received within the housing for reciprocation in a plane generally perpendicular to the central axis;
and
e. first cylinder means mounted to the housing and actuated by the slide for reciprocating the counterweight means in the opposite direction of and in synchronization with the slide reciprocation.

7 more elements

Dependencies are inferred from the claim text.

Dynamically compensating counterbalance

Life of this patent

Dynamically compensating counterbalance

Life of this patent

Abstract

Claims44