Rotary hammer with variable hammering stroke

A rotary hammer, comprising:

• a pneumatic hammering mechanism driven by a wobble plate drive arrangement;
• a rotatably driven intermediate shaft having a longitudinal axis about which it rotates;
• said wobble plate drive arrangement including a hub member carried by said intermediate shaft, said hub member being rotated with said intermediate shaft to operate said wobble plate drive arrangement;
• a carrier rotatably mounted on said intermediate shaft and having a bearing portion upon which said hub member is rotatably mounted, said bearing portion defining a rotational axis about which said hub member is relatively rotatable;
• said bearing portion rotational axis being inclined relative to said intermediate shaft longitudinal axis;
• a resilient coupling between said carrier and said intermediate shaft to enable said carrier to be rotationally driven by said intermediate shaft while allowing rotational displacement of said carrier about said intermediate shaft;
• and
• said resilient coupling comprising a spring, said spring having two ends attached respectively to said intermediate shaft and said carrier.

A rotary hammer, comprising:

• a rotatable drill spindle carrying a tool holder;
• a hammering mechanism driven by a wobble plate drive arrangement to produce a hammering stroke;
• a rotatable intermediate shaft drivingly connected to said drill spindle for rotation thereof via a carrier member mounted on said intermediate shaft;
• said wobble plate drive arrangement including a hub member rotatably mounted on a bearing portion of said carrier member, said bearing portion defining a rotational axis which is inclined to a longitudinal axis of said intermediate shaft;
• said carrier member being rotatably mounted on said intermediate shaft, but coupled thereto for rotation therewith by a resilient coupling;
• and
• said resilient coupling having a part attached to said intermediate shaft and another part attached to said carrier member to enable stressing of said resilient coupling by rotational displacement of said carrier member relative to said intermediate shaft, rotational displacement of said carrier member relative to said intermediate shaft due to change of loading on said drill spindle effecting a corresponding change in said hammering stroke.

A rotary hammer, comprising:

• a rotatable drill spindle carrying a tool holder;
• a hammering mechanism driven by a wobble plate drive arrangement to produce a hammering stroke;
• a rotatable intermediate shaft drivingly connected to said drill spindle for rotation thereof via a carrier member mounted on said intermediate shaft;
• said wobble plate drive arrangement including a hub member rotatably mounted on a bearing portion of said carrier member, said bearing portion defining a rotational axis which is inclined to a longitudinal axis of said intermediate shaft;
• said carrier member being rotatable mounted on said intermediate shaft, but coupled thereto for rotation therewith by a resilient coupling, rotational displacement of said carrier member relative to said intermediate shaft due to change of loading on said drill spindle effecting a corresponding change in said hammering stroke;
• said resilient coupling comprising a spring;
• and
• said spring comprising a coil spring encircling said intermediate shaft with ends of the coil spring being respectively secured to said intermediate shaft and said carrier member.

A rotary hammer, comprising:

• a hammering mechanism driven by a wobble plate drive arrangement;
• a rotatably driven intermediate shaft having an axis about which it rotates;
• said wobble plate drive arrangement including a hub member carried by said intermediate shaft, said hub member being rotated with said intermediate shaft to operate said wobble plate drive arrangement;
• a carrier rotatable relative to said intermediate shaft and having a bearing portion upon which said hub member is rotatably mounted, said bearing portion defining a rotational axis about which said hub member is relatively rotatable;
• said bearing portion rotational axis being inclined with respect to said intermediate shaft axis;
• and
• a spring encircling said intermediate shaft and having two ends attached respectively to said intermediate shaft and said carrier to enable said carrier to be rotationally driven by said intermediate shaft via said spring while allowing rotational displacement of said carrier relative to said intermediate shaft in dependence upon changes in load on said spring.

A rotary hammer, comprising:

• a rotatable tool holder;
• a hammering mechanism driven by a wobble plate drive arrangement to produce a hammering stroke;
• a rotatably driven intermediate shaft through which torque for rotating the tool holder is transmitted, said intermediate shaft having a longitudinal axis about which it is rotatable;
• said wobble plate drive arrangement including a rotatably driven hub body mounted on said intermediate shaft;
• said hub body, at least in a hammering mode of the rotary hammer, being held non-rotatable relative to said intermediate shaft;
• a carrier sleeve rotatably mounted on said intermediate shaft;
• a coil spring encircling said intermediate shaft with ends of the coil spring respectively secured to said intermediate shaft and said carrier sleeve;
• said hub body being mounted on a portion of said carrier sleeve for rotation relative to said carrier sleeve portion about a longitudinal axis thereof, said carrier sleeve portion longitudinal axis being inclined relative to said intermediate shaft longitudinal axis;
• and
• means for drivingly connecting said carrier sleeve to said tool holder for said rotating of the tool holder whereby rotational displacement of said carrier sleeve relative to said intermediate shaft due to change of loading on said tool holder effects automatically via said coil spring a consequential change in said hammering stroke.

A rotary hammer, comprising:

• a rotatable tool holder;
• a pneumatic hammering mechanism driven by a wobble plate drive arrangement;
• a rotatably driven intermediate shaft through which torque for rotating the tool holder is transmitted, said intermediate shaft having a longitudinal axis about which it is rotatable;
• said wobble plate drive arrangement including a rotatably driven hub body mounted on said intermediate shaft;
• said hub body, at least in a hammering mode of the rotary hammer, being held non-rotatable relative to said intermediate shaft;
• a carrier sleeve rotatably mounted on said intermediate shaft and connected to the latter through a coupling elastically deformable in a circumferential direction about said shaft;
• said carrier sleeve having a gear portion for transmitting said torque for said tool holder from said intermediate shaft to a rotatable gear element;
• said hub body being mounted on a portion of said carrier sleeve for rotation relative to said carrier sleeve portion about a longitudinal axis thereof, said carrier sleeve portion longitudinal axis being inclined relative to said intermediate shaft longitudinal axis;
• and
• said elastically deformable coupling comprising a coil spring located coaxially in relation to said intermediate shaft, one end of said coil spring being connected to said intermediate shaft and an other end of said coil spring being connected to said carrier sleeve.

A rotary hammer, comprising:

• a rotatable tool holder;
• a pneumatic hammering mechanism driven by a wobble plate drive arrangement;
• a rotatably driven intermediate shaft through which torque for rotating the tool holder is transmitted, said intermediate shaft having a longitudinal axis about which it is rotatable;
• said wobble plate drive arrangement including a rotatably driven hub body mounted on said intermediate shaft;
• said hub body, at least in a hammering mode of the rotary hammer, being held non-rotatable relative to said intermediate shaft;
• a carrier sleeve rotatably mounted on said intermediate shaft and connected to the latter through a coupling elastically deformable in a circumferential direction about said shaft;
• said carrier sleeve having a gear portion for transmitting said torque for said tool holder from said intermediate shaft to a rotatable gear element;
• said hub body being mounted on a portion of said carrier sleeve for rotation relative to said carrier sleeve portion about a longitudinal axis thereof, said carrier sleeve portion longitudinal axis being inclined relative to said intermediate shaft longitudinal axis;
• said hub body and said intermediate shaft being in non-rotatable engagement through coupling projections;
• and
• said coupling projections on the one hand being provided on an end surface of said hub body and on the other hand being provided on a driving gear non-rotatably mounted on said intermediate shaft.