Method of producting an electric contact
AssigneeHitachi, Ltd.
InventorsTatsuhiro Tani, Masaaki Ishiguri, Rokuro Kikuchi, Akio Ohyama
Life of this patent
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Abstract
A method of production of an electric contact including a contact base member of one metal and a contact member of another metal of hardness lower than that of the contact base member joined to the contact member at one end portion thereof, with the method comprising the steps of forming a blind hole at the one end portion of the contact base member and applying pressure simultaneously to the contact base member and the contact member after the contact member is inserted and filled in the blind hole, to thereby cause the metals of the two members undergo plastic deformation to join them together in intimate contact with each other.
Claims8
A method of producing an electric contact, the method comprising the steps of:
- providing a contact base member of one metal, which base member has an axially extending blind hole;
- providing a contact member of another metal of hardness lower than a hardness of the contact base member which contact member has a columnar shaped portion insertable into the blind hole and a height greater than a depth of the blind hole;
- inserting the contact member into the blind hole of said contact base member;
- applying axial pressure to the contact member to fill the blind hole with the contact member, an intimate contact interface area being formed between the contact member and a whole portion of the blind hole;
- and
- applying axial pressure subsequent to the filling of the blind hole of the contact base member with the contact member, plastically axially compression-deforming both the contact member and the contact base member simultaneously, increasing, by the simultaneous plastic compression deformation of both said contact member and said contact base member, said initial intimate contact interface area into a final contact interface area larger than said initial contact interface area while changing an axial sectional shape of the interface defined between a wall of the blind hole and the contact member into a trapezoidal shape with the smallest side of the shape being the side adjoining said contact member, wherein an electrically superior contact state as well as a firm mechanical engagement between the contact member and the contact base member is achieved.
A method of production of an electric contact including a contact base member of one metal and a contact member of another metal of hardness lower than a hardness of the contact base member united to the contact base member at one end portion, thereof, the method comprising the steps of:
- preparing the contact base member shaped to have a head and a rod portion extending from said head;
- forming a blind hole of a predetermined volume in the head of said control base member along a center axis of said contact base member;
- preparing the contact member shaped to have a columnar portion insertable in said blind hole and projecting outwardly of said blind hole and above the head when inserted in the blind hole;
- inserting the contact member into the blind hole of the contact base member;
- holding the underside of the head of the contact base member and the rod portion thereof by lower dies;
- and
- applying axial pressure to the contact member to plastically deform the contact member to fill the blind hole with the contact member;
- and
- applying axial pressure subsequent to the filling of the blind hole of the contact base member with the contact member so as to plastically axially-compression deform the contact member and contact base member simultaneously thereby increasing by the simultaneous plastic compression-deformation of both of said contact member and said contact base member an initial intimate contact interface area into a final contact interface area larger than said initial contact interface area while changing an axial sectional shape of the interfce defined between a wall of the blind hole and the contact member into a trapezoidal shape with the smallest side of said shape being the side adjoining said contact member, whereby an electrically superior contacting state as well as a firm mechanical engagement between the contact member and the contact base member is achieved.
A method of producing an electric contact including a contact base member of one metal and a contact member of another metal of a hardness lower than that of the contact base member joined to the contact base member at one end portion thereof, the method comprising the steps of:
- preparing the contact base member shaped have a head and rod portion extending from said head;
- forming a blind hole of a predetermined volume in the head of said contact base member along a center axis of said contact member;
- preparing the contact member insertable in said blind hole having a portion extending outwardly of the blind hole above the head by a predetermined volume when inserting in the blind hole;
- holding an underside of the head of the contact member and the rod portion thereof by lower dies;
- inserting the contact member in the blind hole and then applying pressure simultaneously to the two metals axially of the blind hole by an upper die formed with a recess for accommodating a projection of the contact member, said recess being essentially of the same volume as said projection, to plastically deform the contact member to fill the blind hole while the projection of the contact member extends in a predetermined proportion from the head;
- and
- applying axial pressure subsequent to the filling of the blind hole so as to cause the projection of the contact member extending from the head and the contact base member to further undergo plastic deformation at the same time so that an initial intimate contact in interface area between the contact base member and the contact member is changed into a final contact interface area greater than the initial intimate contact interface area while changing an axial sectional shape of the interface defined between the wall of the blind hole and the contact member into a trapezoidal shape with the smallest side of said shape being the side adjoining the contact member, whereby an electrically superior contact state as well as a firm mechanical engagement between the contact member and the contact base member is achieved.
Dependencies are inferred from the claim text.