Motor commutator dust shield member for use in an electrically operated drilling device

Claim 2

In an electrically operated drilling device, such as used in rock drilling or chiseling operations, comprising a housing, a commutator motor positioned within said housing, said commutator motor including a commutator, carbon brushes positioned around said commutator in angularly spaced relation to one another, a carbon holder located within said housing and arranged to mount said carbon brushes in juxtaposition to said commutator, a motor shaft extending from said motor, a fan blade mounted on said motor shaft for rotation therewith, inlet openings located in one part of said housing, outlet openings located in said housing spaced from said inlet openings so that air can be drawn into said housing by said fan blade through said inlet openings circulated over said commutator motor and exhausted through said outlet openings for cooling said commutator motor, wherein the improvement comprises a shield positioned within said housing and disposed about said commutator to protect it from contact by foreign particles contained in the cooling air circulating through said housing, said shield and said carbon holder joined together as a unitary member, the unitary structure of said shield and carbon holder comprises a first ring-shaped member located within and extending around the inner surface of said housing, a second ring-shaped member in coaxial relationship with said first ring-shaped member spaced radially inwardly from said first ring-shaped member, connecting webs extending between said first and second ring-shaped member and completely enclosing said carbon brushes, and the inner surface of said first ring-shaped member and the opposing surfaces of said connecting webs and said second ring-shaped member defining openings for the passage of air through said housing.

Claim 3

In an electrically operated drilling device, as set forth in claim 1, wherein said carbon brushes extend outwardly from said commutator transversely of the axial direction of said shaft, and the unitary structure of said shield and carbon holder being formed of an insulating material with said carbon holder completely enclosing said carbon brushes.

Claim 4

In an electrically operated drilling device, as set forth in claim 1, wherein the unitary structure of said shield and carbon holder is formed of an insulating material.

Claim 5

In an electrically operated drilling device, such as used in rock drilling or chiseling operations, comprising a housing, a commutator motor positioned within said housing, said commutator motor including a commutator, carbon brushes positioned around said cOmmutator in angularly spaced relation to one another, a carbon holder located within said housing an arranged to mount said carbon brushes in juxtaposition to said commutator, a motor shaft extending from said motor, a fan blade mounted on said motor shaft for rotation therewith, inlet openings located in one part of said housing, outlet openings located in said housing spaced from said inlet openings so that air can be drawn into said housing by said fan blade to said inlet openings circulated over said commutator motor and exhausted through said outlet openings for cooling said commutator motor, wherein the improvement comprises a shield positioned within said housing and disposed about said commutator to protect it from contact by foreign particles contained in the cooling air circulating through said housing, said housing is generally cylindrically shaped with its cylindrical axis arranged in generally parallel relation with the axis of said motor shaft, said inlet and outlet openings being spaced apart in the axial direction of said motor shaft with said commutator located between said inlet and outlet openings, said shield being ring-shaped and having its axis extending parallel with the axis of said motor shaft, said shield laterally enclosing the sides of said commutator which extend in the axial direction of said motor shaft, said carbon brushes extend upwardly from said commutator transversely of the axial direction of said motor shaft, said carbon holder and shield formed as a unitary member of an insulating material with said carbon holder completely enclosing said carbon brushes, said carbon holder comprises a first ring-shaped member coaxial with the cylindrical axis of said housing and disposed in surface contact with the inwardly facing surface of said housing, said shield comprises a second ring-shaped member coaxial with said motor shaft and disposed about and laterally enclosing the surfaces of said commutator extending in the axial direction of said motor shaft, and said carbon holder includes connecting webs connected to and extending between said first and second ring-shaped members for completely enclosing said carbon brushes.

Claim 6

In an electrically operated drilling device, such as used in rock drilling or chiseling operations, comprising a housing, a commutator motor positioned within said housing, said commutator motor including a commutator, carbon brushes positioned around said cOmmutator in angularly spaced relation to one another, a carbon holder located within said housing an arranged to mount said carbon brushes in juxtaposition to said commutator, a motor shaft extending from said motor, a fan blade mounted on said motor shaft for rotation therewith, inlet openings located in one part of said housing, outlet openings located in said housing spaced from said inlet openings so that air can be drawn into said housing by said fan blade to said inlet openings circulated over said commutator motor and exhausted through said outlet openings for cooling said commutator motor, wherein the improvement comprises a shield positioned within said housing and disposed about said commutator to protect it from contact by foreign particles contained in the cooling air circulating through said housing, said housing is generally cylindrically shaped with its cylindrical axis arranged in generally parallel relation with the axis of said motor shaft, said inlet and outlet openings being spaced apart in the axial direction of said motor shaft with said commutator located between said inlet and outlet openings, said shield being ring-shaped and having its axis extending parallel with the axis of said motor shaft, said shield laterally enclosing the sides of said commutator which extend in the axial direction of said motor shaft, said carbon brushes extend upwardly from said commutator transversely of the axial direction of said motor shaft, said carbon holder and shield formed as a unitary member of an insulating material with said carbon holder completely enclosing said carbon brushes, said carbon holder comprises a first ring-shaped member coaxial with the cylindrical axis of said housing and disposed in surface contact with the inwardly facing surface of said housing, said shield comprises a second ring-shaped member coaxial with said motor shaft and disposed about and laterally enclosing the surfaces of said commutator extending in the axial direction of said motor shaft, and said carbon holder includes connecting webs connected to and extending between said first and second ring-shaped members for completely enclosing said carbon brushes.

Claim 7

In an electrically operated drilling device, as set forth in claim 4, said carbon holder and shield form a plurality of openings extending in the axial direction of said motor shaft and the openings are defined by the inwardly facing surface of said first ring-shaped member, the outwardly facing surfaces of said second ring-shaped member and the surfaces of said connecting webs extending between said first and second members and facing away from said carbon brushes.