Tool carriage advance and retraction control

regenerative members operatively associated with said adder members and producing, in conjunction with said reversible first drive means, said rapid return stroke which is the sum of said previous rapid advance stroke and said previous feed stroke, said regenerative members operating on said adder members to positively return said adder members to a non-extended

• position during said rapid return stroke. 2. In a machine tool feed system which comprises a slide base and a tool supporting sliding carriage movably mounted thereon and in which the motion pattern of said carriage comprises a first rapid advance stroke which moves the carriage and tools forward at a relatively high speed to bring the tools into close proximity to the workpiece, and a second forward feed stroke, at the end of the rapid advance stroke, with a relatively slow constant speed during which motion the tools are fed into the workpiece, and a rapid return stroke at a relatively high speed for a return stroke which is the sum of the rapid advance and feed strokes, a drive system for said carriage comprising:
• (a) a first drive means mounted to said slide base which generates a fixed stroke smoothly accelerated-decelerated reversible output motion, said first drive means being selectively coupled to said carriage in a fixed ratio to generate a predetermined stroke smoothly accelerated-decelerated rapid advance stroke of said carriage for one direction of output of said first drive means, and said first drive means being selectively regeneratively coupled to said carriage in a variable ratio to generate a variable stroke, smoothly accelerated-decelerated rapid return stroke of said carriage for the other direction of output of said first drive means, with said rapid return stroke of said carriage equal to the sum of said previous rapid advance stroke and said feed stroke of said carriage,
• (b) a second drive means mounted to said slide base and selectively coupled to said carriage to generate a predetermined length constant speed feed stroke of said carriage,
• (c) shift means, operatively associated with said first drive means and said second drive means which couples said first drive means to said carriage and uncouples said second drive means from said carriage during said rapid advance stroke, and uncouples said first drive means from said carriage and couples said second drives means to said carriage during said feed stroke, and uncouples said second drive means from said carriage during said rapid return stroke, and
• (d) adding means operatively associated with said carriage and said first drive means comprising:
• 1. a first regenerative member mounted to said slide base,
• 2. multiple movably interconnected adder members interposed between and operatively connecting said first drive means and said carriage, and
• 3. a second regenerative member mounted to one of said multiple movably interconnected adder members,
• whereby said multiple movably interconnected adder members operate in three modes:
• a locked mode in which said multiple movably interconnected adder members are locked with respect to each other in a normal relationship and movable as a combined single body thereby transmitting the motion generated by said first drive means, operating in said one direction, to said carriage in a fixed ratio for said rapid advance stroke;
• an unlocked mode in which said multiple movably interconnected adder members are unlocked and are free to move with respect to each other from their said normal relationship to a spaced relationship as said carriage is actuated by said second drive means for said feed stroke while said first drive means is inoperative;
• and a regenerative mode in which said multiple movably interconnected adder members are driven from their spaced relationship to their normal relationship by said regenerative members as said first drive means, operating in said other direction, drives said carriage through said multiple movably interconnected adder members for a rapid return stroke of said carriage which is the sum of the previous said rapid advance stroke and the previous said feed stroke.

In a machine tool feed system which comprises a base and a tool supporting carriage movably mounted on said base and in which the motion pattern of said carriage comprises a first forward rapid advance stroke which displaces the carriage forwardly from a predetermined retracted start position to a predetermined intermediate position at a relatively high speed to advance the tool thereon into close proximity to the workpiece, a second forward feed stroke at the end of the rapid advance stroke wherein the tool is fed forwardly from said intermediate position at a relatively slow constant feed into the workpiece and then a third rapid return stroke wherein the carriage is returned to said retracted start position at a relatively high speed, a drive system for the carriage comprising:

• (a) a first drive means mounted to said base and adapted to generate a relatively rapid, smoothly accelerated-decelerated reversible output motion,
• (b) a second drive means mounted to said base and adapted to generate a predetermined relatively slow constant speed output motion,
• (c) first means for connecting the first drive means with the carriage to impart to the carriage said rapid advance and rapid return strokes,
• (d) second means for connecting the second drive means to the carriage to impart to the carriage said feed stroke, said first connecting means including a first output member reversibly driven by the first drive means during rapid advance and rapid return strokes and a second output member connected to the carriage in driving relation, said first and second output members being operably connected together for movement relative to each other, said first drive means causing said first output member to assume a predetermined start position relative to said base when the carriage is in said retracted start position,
• (e) latch means for locking said output members together in a predetermined fixed position relative to one another during the rapid advance stroke so that they move as a unitary member and thus cause displacement of the carriage substantially proportional to the displacement of the first output member during said rapid advance stroke,
• (f) means for releasing said latch means at the end of said rapid advance stroke to permit one of said output members to move relative to the other output member during the feed stroke when the carriage is being displaced by the second drive means,
• (g) regenerative means responsive to the reverse movement of the first output member during the rapid return stroke for moving said one output member back to said predetermined fixed position relative to the other output member to thereby return the carriage to said retracted start position when the first output member is returned to its start position by the first drive means, and
• (h) and shift means operable to selectively and singly couple one of said drive means with said carriage.