received by the International Bureau on 16 August 2013 (16.08.2013)

1. A punch and die assembly for use in a punch press having an opening for holding the punch assembly, said punch assembly comprising:

a guide sleeve adapted to be mounted on the punch press; a punch shank mounted for sliding movement in the guide sleeve and including an insert having a punch point at a lower end thereof for forming or punching a workpiece;

said insert comprising a separate removable punch point element having an upwardly extending head portion,

said punch shank having a downwardly opening recess therein to receive the head portion of the removable insert,

said punch shank having an access port in a sidewal] thereof; a manually operable latch element mounted within the punch shank above the insert for engagement with the head of the insert and having at least one laterally movable locking surface positioned to engage a confronting downwardly facing cooperating locking surface as a part of the head of said insert,

the latch element having at least one manually moveable operating member comprising a rotatable cam that is accessible through the port in the punch shank,

the latch element being constructed and arranged on the punch shank to engage the head of the insert such that moving the opening member through the port in the shank will force the latch element by a wedging action to contact the head with a fit so as to eliminate any clearance therebetween, and

the manually movable cam being operatively connected to the latch element for pressing the latch element to an insert engaging position so as to retain the head of the insert within the downwardly facing opening in the lower end of the punch shank.

2. A punch and die assembly for use in a punch press having an opening for holding the punch assembly, said punch assembly comprising:

a guide sleeve adapted to be mounted on the punch press;

16 a punch shank mounted for sliding movement in the guide sleeve and with an insert having a punch point at a lower end thereof for forming or punching a workpiece;

said insert comprising a separate removable punch point element 5 having an upwardly extending head portion,

said punch shank having a downwardly opening recess therein to receive the head portion of the removable insert,

said punch shank having an access port in a sidewall thereof;

a manually operable latch element mounted within the punch shank 0 above the insert for engagement with the head of the insert and having at least one laterally movable locking surface positioned to engage a confronting downwardly facing cooperating locking surface as a part of the head of said insert,

the latch element having at least one manually moveable operating member that is accessible through the port in the punch shank,

S the latch element being constructed and arranged on the punch shank to engage the head of the insert such that moving the operating member through the port in the shank will force the latch element by a wedging action to contact the head with a fit so as to eliminate any clearance therebetween, and

the manually movable operating member being operatively connected0 to the latch element for pressing the latch element to an insert engaging position so as to retain the head of the insert within the downwardly facing opening in the lower end of the punch shank and the latch element is mounted to slide transversely through the punch shank for engagement with the head of the insert. 3 3. The combination of claim 1 wherein the latch element comprises a pair of latch levers pivotally mounted and thereon biased for being moved into engagement with the head portion of the insert.

4. The punch and die assembly of claim 3 and further including at least0 one compression springpushing on each latch lever for normally biasing the pair of latch levers out of engagement with the annular groove.

5. The punch and die assembly of claim 4 wherein the rotatable cam cooperates with the pair of latch levers for bringing the latch levers into locking

17 engagement with the annular groove against the force exerted by the compression springs.

6. The punch and die assembly of claim 5 and further including a detent element to prevent rotation of the rotatable cam during a punching operation.

7. The punch and die assembly of claim 2 wherein the latch element comprises a plate having first and second overlapping apertures, the first aperture being of a diameter greater than a diameter of said head portion and the second aperture of a diameter less than the diameter of the head portion.

8. The punch and die assembly of claim 2 wherein the latch element is resiliently held in place by means of a spring loaded detent. 9. The punch and die assembly of claim 2 wherein the latch element cooperates with sidewalls of the guide to prevent lateral movement thereof.

10. The punch and die assembly of claim 3 wherein the head portion of the insert includes a concentric bore and an annular recess in the bore and where ends of the latch levers releasably engage the walls defining the annular recess.

11. The punch and die assembly of claim 10 wherein the rotatable cam coupled to the operating member controls the positioning of the ends of the latch levers.

12. The punch and die assembly of claim I wherein the latch element comprises a pair of latch levers pivotally mounted in diametrically positioned vertical slots formed inward from a peripheral surface of the punch shank proximate said downwardly opening recess.

13. The punch and die assembly of claim 12 wherein the head portion of the insert includes an annular groove in the periphery thereof adapted to be engaged by the pair of latch levers when the head portion is inserted into the downwardly opening recess.

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14. The punch and die assembly of claim 13 and further including a compression spring disposed between the pair of latch levers for normally biasing the pair of latch levers out of engagement with the annular groove.

15. The punch and die assembly of claim 14 wherein the rotatable cam cooperates with the pair of latch levers for bringing the latch levers into locking engagement with the annular peripheral groove against the force exerted by the compression spring.

16. The punch and die assembly of claim 15 and further including a detent element to prevent rotation of the rotatable cam during a punching operation.

17. A punch and die assembly for use in a punch press having an opening for holding the punch assembly, said punch assembly comprising:

a guide sleeve adapted to be mounted on the punch press; a punch shank mounted for sliding movement in the guide sleeve and with an insert having a punch point at a lower end thereof for forming or punching a workpiece;

said insert comprising a separate removable punch point element having an upwardly extending head portion,

said punch shank having a downwardly opening recess therein to receive the head portion of the removable insert,

said punch shank having an access port in a sidewall thereof;

a manually operable latch element mounted within the punch shank above the insert for engagement with the head of the insert and having at least one laterally movable locking surface positioned to engage a confronting downwardly facing cooperating locking surface as a part of the head of said insert,

the latch element having at least one manually moveable operating member that is accessible through the port in the punch shank,

the latch element being constructed and arranged on the punch shank to engage the head of the insert such that moving the operating member through the port in the shank will force the latch element by a wedging action to contact the head with a fit so as to eliminate any clearance therebetween, and

19 the manually movable operating member being operatively connected to the latch element for pressing the latch element to an insert engaging position so as to retain the head of the insert within the downwardly facing opening in the lower end of the punch shankand wherein the head portion includes a cone shaped portion and inwardly and upwardly tapered recess on opposed side surfaces thereof defining upper abutment edges and the manually operable latch element comprises a pair of intercoupled slidable actuators having camming slots formed therein, the camming slots adapted to engaged a pair of latch plates where the latch plates extend between the abutment edges and arcuate groove on the shank when the slidable actuators are in a first position and are disengaged from the abutment edges when the slidable actuators are in a second position.

18. The punch and die assembly of claim 17 wherein the pair of slidable actuators is disposed on a dowel pin that extends through a vertical slot formed through a portion of the shank and the slidable actuators reside in pockets formed inward from a peripheral surface of the shank.

19. The punch and die assembly of claim 17 and further including a cone shaped cylindrical pocket with a flexible end membrane formed in a bottom end of the shank for receiving the cone shaped portion of the punch head to provide precision centering as the locking mechanism is engaged.

20. The punch and die assembly of claim 19 wherein the head further includes a second precision fit cylindrical portion disposed above the cone shaped portion of the punch head to provide redundancy in supporting side loading.

21. The punch and die assembly of claim 1 wherein the cam element is located on a supporting shaft that is journaled for rotation within a bore in the punch shank and the shaft having a manually accessible knob recessed within an access port in a sidewall of the punch shank.

22. The punch and die assembly of claim 1 wherein the cam is a twin lobed cam having a pair of lobes spaced 180° apart, the cam is supported for rotation upon bearing surfaces that comprise the shaft and the bore in the shank.

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23. The punch and die assembly of claim 21 wherein the shaft includes a hand tool connection element such that the operating member can be moved manually by the knob or moved manually by a hand tool which is secured to the tool connector element.

24. The punch and die assembly of claim 23 wherein the tool connector element is a hex socket formed on an end of the shaft opposite from the cam element.

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