A clutch device includes a guiding element, a first clutch element being capable of sliding relative to the guiding element, a second clutch element being capable of sliding relative to the guiding element, an elastic element including a first connecting leg and a second connecting leg which are respectively connected with the first clutch element and the second clutch element, and a rotating element being capable of rotating about a first axis relative to the guiding element. The rotating element includes a first supporting portion for contacting with the first connecting leg, which is disposed at a first axial position of the first axis, and a second supporting portion for contacting with the second connecting leg, which is disposed at a second axial position of the first axis.

A hammer drill includes a motor, a cylindrical tool holder, an intermediate shaft, a rotation conversion portion, a mode switching member, a restricting member, and an operation member. A first switch state of the restricting member by the operation member causes a first operation mode in which rotation of the tool holder and a striking motion of a striking portion allowed to be performed simultaneously in conjunction with retreat of the tool holder. A second switch state of the restricting member by the operation member causes a second operation mode in which the retreat of the tool holder from the advance position is restricted and the tool holder is allowed to be rotated only. The restricting member is provided with a plurality of restricting portions that contact the mode switching member to restrict the retreat of the mode switching member.

A cam operated apparatus with a cam track (16) and cam follower (12) being engaged with one another, a head element such as a bit operatively connected to the cam track or cam follower means, and rotational drive means such as a motor operatively connected to the other, such that rotational drive causes reciprocal action of the head element and the width (A) of the cam follower means (12) is in the region of 91% to 99%, of the width (B) of the cam track (16), to create a harmonic effect on the head element with low noise and increased power efficiency. Pin-in-wave and wave-in-wave arrangements are described along with tools including the cam operated apparatus.

A hammer drill includes a motor, a cylindrical tool holder, an intermediate shaft, a rotation conversion portion, a mode switching member, a restricting member, and an operation member. A first switch state of the restricting member by the operation member causes a first operation mode in which rotation of the tool holder and a striking motion of a striking portion allowed to be performed simultaneously in conjunction with retreat of the tool holder. A second switch state of the restricting member by the operation member causes a second operation mode in which the retreat of the tool holder from the advance position is restricted and the tool holder is allowed to be rotated only. The restricting member is provided with a plurality of restricting portions that contact the mode switching member to restrict the retreat of the mode switching member.

A cam operated apparatus with a cam track and cam follower being engaged with one another, a head element such as a bit operatively connected to the cam track or cam follower means, and rotational drive means such as a motor operatively connected to the other, such that rotational drive causes reciprocal action of the head element and the width of the cam follower means is in the region of 91% to 99%, of the width of the cam track, to create a harmonic effect on the head element with low noise and increased power efficiency. Pin-in-wave and wave-in-wave arrangements are described along with tools including the cam operated apparatus.

A universal chisel attachment is an apparatus designed to convert the torque generated by an electric tool into a reciprocal linear motion to drive a chisel member. The apparatus includes a socket adapter, a chisel assembly, a hammering cam mechanism, and a tubular housing. The socket adapter enables the rotational connection of the hammering cam mechanism to a mounting mechanism of the electric tool. The socket adapter also enables the apparatus to be secured to the electric tool. The hammering cam mechanism converts the torque generated by the electric tool to a reciprocal linear motion of the chisel assembly. The chisel assembly enables the carving or cutting of the target object with the apparatus. The tubular housing enables the unobstructed operation of the hammering cam mechanism during operation. The tubular housing also safely retains all the moving components of the hammering cam mechanism to protect the user during operation.

The present disclosure elaborates on a prior disclosure related to making a powered impact device. That device could optionally attach to a power tool, have adjustable energy per impact, or have an elongated body so the impact energy is generated close to the impact target. The present disclosure relates to a design of the impacting device using a barrel cam to increase the stroke length and make the stroke length adjustable. Further, the present disclosure also relates to several safety features of the impacting device. These safety features include the ability to discharge any stored energy when not in use, the ability not to be damaged when the drive shaft is driven in the wrong direction, and a push to activate feature that reduces the chances of a potentially destructive air strike. Further, the present disclosure elaborates on alternative tool heads.