It is enabled to facilitate fine adjustment of power as well as reduction of the amount of movement required to maximize the power. An actuator 13 is moved by operation of a user. A pressure sensitive sensor 15 detects applied pressing force. A pressing member 14 presses the pressure sensitive sensor 15. When the amount of movement of the actuator 13 is smaller than a predetermined amount, the pressing member 14 presses the pressure sensitive sensor 15 to apply force corresponding to the amount of movement of the actuator 13. When the amount of movement of the actuator 13 is not smaller than the predetermined amount, the pressing member 14 presses the pressure sensitive sensor 15 to apply force corresponding to pressing force applied to the actuator 13 by the user.

The switch opening-closing mechanism, which makes it possible to increase a contact force so as to improve a vibration resistance, includes a sliding part, a second movable piece, and a second fixed contact. In a case where an amount of movement of a sliding part reaches a second retraction amount, the second movable piece comes into contact with the second fixed contact due to a spring force applied to the second movable piece. In a case where the amount of movement of the sliding part reaches a third retraction amount which is larger than a second retraction amount, the sliding part presses the second movable piece against the second fixed contact.

The present disclosure introduces apparatus and related methods pertaining to a first electrical power cable, a second electrical power cable, and a set of breakers. The first and second electrical power cables each extend a variable distance between a static system at a wellsite and a movable system at the wellsite. The breakers are operable to select either of the first and second electrical power cables to couple electrical power from a stationary electrical power source at the static system to a load at the movable system.

An electrical connector can be provided for connecting a power source to an insertable conductor, including an igniter for exothermic weld material. One or more conductors can be disposed within a housing that is configured to receive the insertable conductor. An actuator can be engaged from outside the housing to move at least one of the conductors within the housing between resting and actuated orientations.

A housing includes a case member having an opened front face, and a cover member firmly fixed with the case member to close the opened front face of the case member. The case member has a penetration hole penetrating its side face. A movable part includes an inner member disposed inside the housing to control a circuit, and an outer member being a discrete piece from the inner member and exposed outside the housing to be manipulated by a user. The outer member includes a shaft part inserted through the penetration hole.

A trigger assembly for use with an electrical device, including a trigger member, an actuator member operably-connected to the trigger member, and a lock-on mechanism for selectably restricting movement of the trigger member relative to the housing.

An electronic module is provided including a circuit board defining a longitudinal axis and having a first surface and a second surface. A module housing is provided having a bottom surface and side walls extending from the bottom surface to form an open face through which the circuit board is received. Power switches configured as an inverter circuit to drive an electric motor are mounted on the second surface of the circuit board facing the bottom surface of the module housing, and a series of heat sinks are discretely mounted on the first surface of the circuit board facing the open face opposite the power switches. Potting material is disposed in the distance between the circuit board and the bottom surface of the module housing to cover the power switches. Thermal vias are disposed through the circuit board between corresponding ones of the heat sinks and the power switches.

An electronic module is provided including power switches mounted on a circuit board and configured as an inverter circuit for an electric motor. A sliding member is coupled to an actuator. A power contact switch is provided including a first conductive body, a second conductive body, and a contact switch. The first and second conductive bodies are mounted on a first surface of the circuit board and include pins received through through-holes of the circuit board to make electrical contact with two conductive tracks on a second surface of the circuit board. The contact switch pivotably is secured to the first conductive body and pivotably moveable by the sliding member to make contact with the second conductive body with movement of the actuator. A flyback diode is electrically connected between the first and second conductive track on the second surface of the circuit board parallel to the power contact switch.

A housing includes a case member having an opened front face, and a cover member firmly fixed with the case member to close the opened front face of the case member. The case member has a penetration hole penetrating its side face. A movable part includes an inner member disposed inside the housing to control a circuit, and an outer member being a discrete piece from the inner member and exposed outside the housing to be manipulated by a user. The outer member includes a shaft part inserted through the penetration hole.

The invention provides an electric drill including a bracket with a handle, a drill rod, a motor assembly, and a switch assembly. The switch assembly includes a first micro switch configured to activate or deactivate the motor assembly, a switch pivotably mounted on the handle through a pivot and cooperating with the first micro switch, and a self-locking button engaged with the switch and configured as: when the self-locking button is in a first state, the self-locking button abuts against the switch to prevent the switch from rotating around the pivot; when the self-locking button is in a second state, the self-locking button is disengaged with the switch, and the switch can rotate around the pivot.