Die pad assembly

Claim 2

A die pad assembly co-operable with a male die for press forming relatively small articles of sheet material, the assembly comprising: a pad holder of a relatively hard elastomeric material, the holder defining a recess extending longitudinally of the holder and end walls closing the ends of said recess, the recess being of a cross-sectional shape to define opposed downwardly convergent wall portions and conforming generally to the shape into which articles are to be formed using the assembly; and, a pad of an elastomeric material softer than the said relatively hard elastomeric material of the holder, the pad being snugly received in said recess in the holder between said end walls and having an upper surface to support an article to be formed, and a lower surface at least parts of which are in surface contact with said convergent wall portions of the said recess in the holder, whereby, in use, an article to be formed is placed on the upper surface of the pad and is engaged by the male die, movement of the die against the article causing the pad to be compressed between the leading extremity of the die and the wall of the recess in the holder to cause the article to bend about the die, the said elastomeric material of the holder being capable of resilient deformation in the event that the die contacts the holder in use.

Claim 3

A die pad assembly as claimed in claim 1, wherein the pad holder is formed around its lower margin with a laterally projecting flange by means of which the holder can be clamped to the bed of a press in use.

Claim 4

An assembly as claimed in claim 2, wherein the pad holder has a front wall and a rear wall in addition to said end walls, and wherein the said flange extends along the lower margins of said end walls and said front wall, said rear wall being plain and defining a reference face on the holder.

Claim 5

An assembly as claimed in claim 1, further comprising a backstop secured to the pad holder, the backstop having a reference face and being adjustable to vary the position of said reference face with respect to said upper surface of the die pad so that an article to be formed can be placed on said surface in contact with said reference face in the appropriate orientation with respect to the path of the male die in use.

Claim 6

An assembly as claimed in claim 4, wherein said backstop is in the form of a pad of an elastomeric material capable of flexing during a forming operation.

Claim 7

An assembly as claimed in claim 1, wherein the said recess in the pad holder includes a pair of mutually inclined side walls disposed symmetrically about a longitudinally extending plane containing the path of travel of the male die, and wherein the lower surface of the pad includes a pair of sides disposed angularly with respect to one another, the angle between these sides being substantially equal to the angle between said side walls, whereby the pad is received in the holder with respective said sides in contact with corresponding said side walls.

Claim 8

An assembly as claimed in claim 1, wherein the said recess in the pad holder is of U-shape in cross-section, and wherein the said lower surface of the pad is of complementary shape in cross-section.

Claim 9

An assembly as claimed in claim 1, wherein the pad holder is made of an elastomeric material of a hardness in the range 50 to 70 on the Durometer D scale.

Claim 10

An assembly as claimed in claim 1, wherein the said pad is made of an elastomeric material of a hardness in one of the following ranges measured on the Durometer A scale: 60-75; 75-85; 85-95.

Claim 11

For use in co-operation with a male die for press forming relatively small articles of sheet material, the combinations of: a pad holder of a relatively hard elastomeric material, the holder defining a recess extending longitudinally of the holder and end walls closing the ends of said recess, the recess being of a cross-sectional shape to define opposed downwardly convergent wall portions and conforming generally to the shape into which articles are to be formed; and a plurality of die pads of respectively different hardnesses for use selectively in association with the pad holder, each pad being made of an elastomeric material softer than the said relatively hard elastomeric material of the holder and being adapted to be snugly received in said recess in the holder between the end walls thereof, each pad further having an upper surface to support an article to be formed, and a lower surface, at least parts of which, when the pad is in use in the holder, are in surface contact with said convergent wall portions of said recess in the holder; whereby, in use, one of said pads is placed in said recess in the holder and an article to be formed is placed on the upper surface of the pad and is engaged by the male die, movement of the die against the article causing the pad to be compressed between the leading extremity of the die and the wall of the recess in the holder to cause the article to bend about the die, the said elastomeric material of the holder being capable of resilient deformation in the event that the die contacts the holder.

Claim 12

For use in co-operation with a male die for press forming relatively small articles of sheet material, the combinations of: a pad holder of a relatively hard elastomeric material, the holder defining a recess extending longitudinally of the holder and end walls closing the ends of said recess, the recess being of a cross-sectional shape to define opposed downwardly convergent wall portions and conforming generally to the shape into which articles are to be formed; and a plurality of die pads of respectively different hardnesses for use selectively in association with the pad holder, each pad being made of an elastomeric material softer than the said relatively hard elastomeric material of the holder and being adapted to be snugly received in said recess in the holder between the end walls thereof, each pad further having an upper surface to support an article to be formed, and a lower surface, at least parts of which, when the pad is in use in the holder, are in surface contact with said convergent wall portions of said recess in the holder; whereby, in use, one of said pads is placed in said recess in the holder and an article to be formed is placed on the upper surface of the pad and is engaged by the male die, movement of the die against the article causing the pad to be compressed between the leading extremity of the die and the wall of the recess in the holder to cause the article to bend about the die, the said elastomeric material of the holder being capable of resilient deformation in the event that the die contacts the holder.

Claim 13

For use in co-operation with a male die and a die pad of an elastomeric material, a pad holder of a relatively hard elastomeric material, the holder defining a longitudinal recess of relatively short axial length and end walls closing the ends of said recess, the recess being of a cross-sectional shape to define opposed downwardly convergent wall portions and conforming generally to the shape into which articles are to be formed by said die.

Claim 14

For use in co-operation with a male die and a die pad of an elastomeric material, a pad holder of a relatively hard elastomeric material, the holder defining a longitudinal recess of relatively short axial length and end walls closing the ends of said recess, the recess being of a cross-sectional shape to define opposed downwardly convergent wall portions and conforming generally to the shape into which articles are to be formed by said die.