Electrical contact for stators in electric tools

Claim 2

An electric tool comprising a housing, a detachable housing cover secured to said housing, an axially displaceable stator located within said housing and secured therein against rotation, means in cooperation with said housing cover for resiliently biasing said stator in its axial direction within said housing, a carbon holder located within said housing, carbon brushes arranged in said carbon holder and disposed in electrical contact with said stator, wherein the improvement comprises contact means in operative association with said biasing means and including separate first contacts and second contacts with said first contacts connected to said carbon brushes and said second contacts connected to said stator so that the biasing action of said biasing means acting in cooperation with said housing cover provides the engagement of said first and second contacts and automatically effects the electrical connection between said carbon brushes and said stator.

Claim 3

An electric tool, as set forth in claim 1, wherein said first contacts are secured to said carbon holder, and a flexible wire connects said first contacts and said carbon brushes.

Claim 4

An electric tool, as set forth in claim 2, wherein said carbon holder having openings therein, said first contacts having claw-shaped projections extending into the openings in said carbon holder and arranged in contacting engagement with said carbon holder.

Claim 5

An electric tool, as set forth in claim 3, wherein said carbon holder comprises a plate member and a cylindrically-shaped section having a plate-like section integral therewith and extending radially inwardly from said cylindrically-shaped section, said cylindrically-shaped section and said plate-like section being formed of an insulating material, said plate member beiNg formed of a conductor material and supported on said plate-like section, the opening in said carbon holder being formed by openings in said plate member in register with recessed portions in said plate-like sections, said first contacts being mounted on said plate member with said claw-shaped projection extending through the openings in said plate member to the recesses in said plate-like section, and said plate-like section having openings therethrough and said plate member having recesses extending into the openings in said plate-like section and into which said carbon brushes are fitted.

Claim 6

An electric tool, as set forth in claim 2, wherein said means for resiliently biasing said stator comprises cylindrical compression springs extending in the axial direction of said stator and located between said stator and said carbon holder within said housing.

Claim 7

An electric tool, as set forth in claim 5, wherein said cylindrical compression springs are secured at one end to said stator, and said second contacts are secured to the opposite ends of said springs from said stator for interengagement with said first contacts.

Claim 8

An electric tool, as set forth in claim 6, wherein said first contacts and said second contacts each have a cup-shaped configuration so that they interfit.

Claim 9

An electric tool, as set forth in claim 7, wherein said second contacts are shaped to fit over said first contacts so that the inner surface of said cup-shaped second contacts seats against the outer surface of said cup-shaped first contacts.

Claim 10

An electric tool, as set forth in claim 8, wherein a curved extension is formed on each of said second contacts and said curved extension partly encloses one coil of said spring at the end which seats against said second contact.

Claim 11

An electric tool, as set forth in claim 9, wherein pin-shaped holding elements formed of an insulating material are secured to said stator and each of said springs is fitted onto one of said holding elements at its end opposite the end supporting said second contacts, and cables extend between said second contacts and said stator.