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US 4,280,359 AGranted
Rotary cam drive for impact tool
AssigneeRobert Bosch GmbH
InventorsWolfgang Schmid, Karl Wanner, Jorg Falchle, Manfred Bleicher, Frank Muller
Life of this patent
Estimating the term…
Abstract
A hammer drill has a housing provided with a tool chuck in which a tool is to be mounted. A drive is provided which is capable of rotating and/or axially impacting the tool chuck. This drive includes a piston reciprocable in axial direction of the tool chuck, a drum rotating on a shaft extending parallel to the direction of reciprocation of the piston and provided with a circumferentially extending cam track, and a transmitting arrangement which travels in part in engagement with the cam track and which has another part connected with the piston to reciprocate the same.
Claims21
A power-driven hammer drill, comprising a housing;
- a tool chuck on said housing and adapted to hold an elongated tool;
- means for impacting said tool chuck in direction lengthwise of the tool, including a member reciprocable in said direction;
- and drive means for said impacting means, comprising a rotatable shaft mounted for rotation about an axis paralleling said direction, a drum coaxially mounted on said shaft for rotation with the same and having a circumferential surface formed with a circumferentially complete cam track, and transmitting means guided by said cam track and operatively connected with said member for transmitting reciprocatory motion to the same in response to rotation of said drum with said shaft;
- means for supporting said rotatable shaft at two locations spaced from one another in an axial direction by a predetermined distance;
- and means for driving said rotatable shaft in rotation and including a driving shaft having a first toothed section, and a second toothed section provided on said drum and engageable with said first toothed section of said driving shaft, said second toothed section of said drum being located between said two locations within said distance so as not to extend axially beyond the latter. PG,30
2 more elements
A power-driven hammer drill, comprising a housing;
- a tool chuck on said housing and adapted to hold an elongated tool;
- means for impacting said tool chuck in direction lengthwise of the tool including a guide tube coaxial with said tool chuck, and a piston which is slidingly received and reciprocable in said guide tube in said direction;
- and drive means for said impacting means, comprising a driven rotatable shaft mounted for rotation about an axis paralleling said direction, a drum coaxially mounted on said shaft freely turnably surrounding the same and having a circumferential surface formed with a circumferentially complete cam track, coupling means for coupling said drum for joint rotation with said shaft, and transmitting means guided by said cam track and operatively connected with said piston for transmitting reciprocatory motion to the same in response to rotation of said drum with said shaft, said coupling means comprising cooperating first and second coupling portions on said shaft and said drum, respectively, and said shaft being axially shiftable relative to said drum between two positions in which said first and second coupling portions are engaged and disengaged, respectively.
A power-driven hammer drill, comprising a housing;
- a tool chuck on said housing and adapted to hold an elongated tool;
- means for impacting said tool chuck in direction lengthwise of the tool, including a member reciprocable in said direction;
- and drive means for said impacting means, comprising a rotatable shaft mounted for rotation about an axis paralleling said direction, a drum coaxially mounted on said shaft for rotation with the same and having a circumferential surface formed with a circumferentially complete cam track, and transmitting means guided by said cam track and operatively connected with said member for transmitting reciprocatory motion to the same in response to rotation of said drum with said shaft, wherein said transmitting means comprises an axially reciprocable rod-like element, a flange surrounding said rod-like element and being rotationally symmetrical relative to the longitudinal axis thereof, and mounting means mounting said flange on said rod-like element for rotation relative to the same about said longitudinal axis, said flange and said rod-like element being formed with juxtaposed inner and outer circumferential recesses, and said mounting means comprising bearing balls in said recesses.
Dependencies are inferred from the claim text.