Portable power tool construction

Claim 2

A power tool comprising an outer housing made of an electrical insulating material and enclosing a motor including an armature shaft and motor bearings, and a power train unit driven by said motor, said power train unit including at least one other shaft driven by said armature shaft, bearings for said other shaft, and a one piece metal bearing block, said shafts being rotatably mounted in their associated bearings, all of said bearings for said other shaft being mounted on said one piece bearing block, and said one piece bearing block being mounted directly on and enclosed by said outer housing.

Claim 3

A power tool comprising a housing, a motor including an armature shaft supported by motor bearings, and a power train unit driven by said motor and including an intermediate shaft and a spindle shaft, bearings for rotatably supporting said spindle and intermediate shafts, and a one piece metal bearing block receiving all of said bearings for said intermediate and spindle shafts, said bearing block being mounted on and within said housing, said shafts having meshing gears, one of said shafts being in offset relation to the other shafts, whereby said shafts and said gears form a compact gear drive train for said power tool.

Claim 4

A power tool comprising a housing, a motor including an armature shaft supported by motor bearings, and a power train unit driven by said motor and including an intermediate shaft and a spindle shaft, bearings for rotatably supporting said spindle and intermediate shafts, and a one piece metal bearing block receiving all of said bearings for said intermediate and spindle shafts, said bearing block being mounted on and within said housing, said shafts having meshing gears, one of said shafts being in offset relation to the other shafts, whereby said shafts and said gears form a compact gear drive train for said power tool.

Claim 5

A power tool as in claim 1, wherein said housing includes a cover half and a support half, said motor and said one piece bearing block being mounted on said support half, said cover half being secured to said support half and enclosing said motor and said power train unit.

Claim 6

A power tool as in claim 1, wherein at least one of said motor bearings is mounted on said bearing block.

Claim 7

A power train unit for a portable tool having a motor and an outer housing formed of an insulating material, said power train unit being adapted to be driven by said motor, and comprising at least two shafts, associated bearings for said shafts, and a metal bearing block, said shafts being supported by said bearings and all of said bearings for all of said shafts being mounted on said bearing block, said bearing block being in one piece and adapted to be secured directly to and enclosed within said insulating outer housing.

Claim 8

A power train unit for a portable tool having a motor and an outer housing formed of an insulating material, said power train unit being adapted to be driven by said motor, and comprising at least two shafts, associated bearings for said shafts, and a metal bearing block, said shafts being supported by said bearings and all of said bearings for all of said shafts being mounted on said bearing block, said bearing block being in one piece and adapted to be secured directly to and enclosed within said insulating outer housing.

Claim 9

A power train unit as in claim 5, wherein said one piece bearing block has a recess formed therein for a bearing of each of said shafts, said recesses receiving said bearings, said power train unit further comprising individual bearing straps for holding each of Said bearings in its associated recess, all of said bearing straps being secured to said one piece bearing block.

Claim 10

A power train unit as in claim 5, and further comprising a shaft driven by said motor, said shafts having meshing gears, one of said shafts being mounted in offset relation to the other of said shafts on said bearing block, whereby said shafts and said gears form a compact gear drive train for said power tool.

Claim 11

A power train unit for a portable tool comprising at least one shaft, at least one bearing for said shaft, and a bearing block, said shaft being rotatably supported by said bearing, said bearing block having a recess formed therein, said recess receiving said bearing, and at least one bearing strap for holding said bearing in said recess, said one bearing strap having one end thereof secured to said bearing block, said one bearing strap including a tab at the other end thereof and said bearing block having a lug formed thereon adjacent said tab, said tab cooperating with said lug to loosely retain said other end of said bearing strap, movement of said bearing forcing said tab into tight engagement with said lug and thus preventing further movement of said bearing.

Claim 12

A power train unit for a portable tool comprising at least one shaft, at least one bearing for said shaft, and a bearing block, said shaft being rotatably supported by said bearing, said bearing block having a recess formed therein, said recess receiving said bearing, and at least one bearing strap for holding said bearing in said recess, said one bearing strap having one end thereof secured to said bearing block, said one bearing strap including a tab at the other end thereof and said bearing block having a lug formed thereon adjacent said tab, said tab cooperating with said lug to loosely retain said other end of said bearing strap, movement of said bearing forcing said tab into tight engagement with said lug and thus preventing further movement of said bearing.

Claim 13

A power train unit for a portable tool having a motor and a housing, said power train unit comprising at least one shaft, at least one bearing for said shaft and a bearing block, said shaft being rotatably supported by said bearing and said bearing being mounted on said bearing block, said bearing block being adapted to be secured to and enclosed within said housing, said one shaft having a reduced diameter portion and said bearing block having a boss portion with an opening coaxial with said reduced diameter portion, said reduced diameter portion rotating in said opening and normally not contacting the margin of said opening, and said reduced diameter portion contacting said margin of said opening when said one shaft is subject to axial forces to prevent excessive radial movement of said reduced diameter portion.

Claim 14

A power train unit for a portable tool having a motor and a housing, said power train unit comprising at least one shaft, at least one bearing for said shaft and a bearing block, said shaft being rotatably supported by said bearing and said bearing being mounted on said bearing block, said bearing block being adapted to be secured to and enclosed within said housing, said one shaft having a reduced diameter portion and said bearing block having a boss portion with an opening coaxial with said reduced diameter portion, said reduced diameter portion rotating in said opening and normally not contacting the margin of said opening, and said reduced diameter portion contacting said margin of said opening when said one shaft is subject to axial forces to prevent excessive radial movement of said reduced diameter portion.

Claim 15

A power train unit as in claim 9, and further comprising a thrust washer on said reduced diameter portion and between said one shaft and said boss, said one shaft abutting said thrust washer which inturn abuts said boss to transfer thrust from said one shaft to said boss.

Claim 16

A power train unit as in claim 9, and further comprising another bearing for said one shaft, a bearing strap having a tab portion, and a lug formed on said bearing block, said tab cooperating with said lug to loosely retain said another bearing on said bearing block.

Claim 17

A power tool comprising an outer housing, a motor having an armature shaft, and a power train unit driven by said motor, said power train unit including an intermediate shaft driven by said armature shaft and a spindle shaft driven by said intermediate shaft, a one piece bearing block, each of said shafts of said power train unit and at least one end of said armature shaft being mounted in said one piece bearing block, said outer housing including a support half and a cover half, said motor and bearing block being secured directly to said support half, said cover half being secured to said support half and enclosing both said motor and bearing block, said outer housing being made of an electrical insulating material, and said bearing block being made of a metal having good heat sink characteristics.

Claim 18

A power tool comprising an outer housing, a motor having an armature shaft, and a power train unit driven by said motor, said power train unit including an intermediate shaft driven by said armature shaft and a spindle shaft driven by said intermediate shaft, a one piece bearing block, each of said shafts of said power train unit and at least one end of said armature shaft being mounted in said one piece bearing block, said outer housing including a support half and a cover half, said motor and bearing block being secured directly to said support half, said cover half being secured to said support half and enclosing both said motor and bearing block, said outer housing being made of an electrical insulating material, and said bearing block being made of a metal having good heat sink characteristics.