Rotary hammer power tool

Claim 2

In a portable power tool of the type adapted to impart rotation and hammering blows simultaneously to an elongated tool element having a shank at one end thereof, the improvement comprising: a. a barrel rotatably mounted in the housing of the power tool; b. a rotary drive formation secured to said barrel at one end thereof for engaging the shank of a tool element when the latter is received in said one end of the barrel thereby to impart rotation to the tool element in response to rotation of the barrel; c. motor means in said housing; d. a cylinder coaxial with said barrel and slidably mounted in the latter adjacent the other end thereof for axial reciprocal movement therein; e. a drive train connecting said cylinder with said motor such that the former is reciprocated upon operation of the latter; f. a cylindrical hammer coaxially disposed within said barrel and mounted therein for pneumatic, reciprocal hammering movement in response to reciprocation of said cylinder, which hammer has a formation arranged to transmit hammering blows to the distal end of said shank; g. a first sleeve coaxially mounted on said barrel for rotation with and relative to the barrel, said first sleeve including a first set of clutch teeth at one end thereof; h. said drive train including gear means on the other end of said first sleeve connecting said first sleeve with said motor means for rotation of the former upon operation of the latter; i. a second sleeve coaxially mounted on said barrel for reciprocal, axial sliding movement relative thereto, which second sleeve is connected to said barrel for imparting rotation thereto, said second sleeve mounting a second set of clutch teeth at one end thereof and arranged for engagement with said first clutch teeth; and j. selector means mounted on the housing of the power tool and engaged with said second sleeve for reciprocating the latter axially thereby to engage and disengage said first and second clutch teeth for selective rotation of said barrel.

Claim 3

The improvement according to claim 1 wherein said first and second sets of clutch teeth are substantially identical and opposite hand versions of each other, each set of clutch teeth being in the form of a plurality of individual teeth arranged in circumferential spaced relation, the open space between adjacent tEeth having an arcuate extent substantially greater than the arcuate extent of each tooth thereby to facilitate the engagement of said first and second sets of clutch teeth at times when said first cylindrical formation is rotating.

Claim 4

In a portable power tool of the type adapted to impart rotation and hammering blows simultaneously to an elongated tool element having a shank at one end thereof, the improvement comprising: a. a barrel rotatably mounted in the housing of the power tool; b. a rotary drive formation secured to the barrel at one end thereof for engaging the shank of a tool element when the latter is received at one end of the barrel thereby to impart rotation to the tool element in response to rotation of the barrel; c. gear means connected to said barrel adjacent the other end thereof for rotation of the barrel in response to rotation of the gear means; d. motor means in said housing including a drive train engaged with said gear means thereby to impart powered rotation thereto; e. a cylinder coaxial with said barrel and slidably mounted in the latter adjacent said other end thereof for axial reciprocal movement therein; f. said drive train including means engaged with said cylinder at one end thereof for reciprocating the same simultaneously with rotation of said gear means; g. a cylindrical hammer coaxial with said cylinder and freely mounted therein for pneumatic, reciprocal hammering movement in response to reciprocation of said cylinder, which hammer has a coaxial extension arranged to project beyond and outwardly of the other end of said cylinder when the latter is in the forward portion of its stroke, which extension is arranged to transmit hammering blows to the distal end of the shank of the tool element; h. said housing of the power tool having wall means cooperating with said barrel to define an annular space therearound, which annular space has an axial extent substantially conterminous with the portion of said barrel in which said cylinder reciprocates; i. seal means closing said annular space from the atomsphere and adapting said annular space to contain a supply of highly viscous lubricating composition, which seal means includes an annular seal engaging said wall means and said barrel to form a seal therebetween, said annular seal defining the forward limit of said annular space; and j. said barrel and said cylinder each having apertures in the walls thereof thereby permitting the aforesaid lubricating composition to enter the barrel and said cylinder thereby to lubricate the cylinder and the hammer.

Claim 5

In a portable power tool of the type adapted to impart rotation and hammering blows simultaneously to an elongated tool element having a shank at one end thereof, the improvement comprising: a. a barrel rotatably mounted in the housing of the power tool; b. a rotary drive formation secured to the barrel at one end thereof for engaging the shank of a tool element when the latter is received at one end of the barrel thereby to impart rotation to the tool element in response to rotation of the barrel; c. gear means connected to said barrel adjacent the other end thereof for rotation of the barrel in response to rotation of the gear means; d. motor means in said housing including a drive train engaged with said gear means thereby to impart powered rotation thereto; e. a cylinder coaxial with said barrel and slidably mounted in the latter adjacent said other end thereof for axial reciprocal movement therein; f. said drive train including means engaged with said cylinder at one end thereof for reciprocating the same simultaneously with rotation of said gear means; g. a cylindrical hammer coaxial with said cylinder and freely mounted therein for pneumatic, reciprocal hammering movement in response to reciprocation of said cylinder, which hammer has a coaxial extension arranged to project beyond and outwardly of the other end of said cylinder when the latter is in the forward portion of its stroke, which extension is arranged to transmit hammering blows to the distal end of the shank of the tool element; h. said housing of the power tool having wall means cooperating with said barrel to define an annular space therearound, which annular space has an axial extent substantially conterminous with the portion of said barrel in which said cylinder reciprocates; i. seal means closing said annular space from the atomsphere and adapting said annular space to contain a supply of highly viscous lubricating composition, which seal means includes an annular seal engaging said wall means and said barrel to form a seal therebetween, said annular seal defining the forward limit of said annular space; and j. said barrel and said cylinder each having apertures in the walls thereof thereby permitting the aforesaid lubricating composition to enter the barrel and said cylinder thereby to lubricate the cylinder and the hammer.