摘要:
A hand tool machine, in particular a drill machine, has a feeler device for determining the diameter of a tool element to be used with the hand tool machine. For measuring the tool elements prior to insertion into the clamping element of the hand tool machine, a feeler device is provided which is arranged separately from the clamping element and is connected with an indicator. The diameter determined by the feeler device is administered to a control unit which is controlling the driving motor. The control unit can also receive in addition further information concerning the material to be treated by means of an input device. In view of the measuring value with regard to the diameter of the tool element and the administered information concerning the material, the optimum rotary speed for the tool element and consequently for the driving motor is determined and adjusted.
摘要:
To prevent bounce of a hammer or plunger element coupled to an insertion blade of a stapling or nailing gun upon return of the plunger element to rest position by a spring (11), the plunger element (4) is in cup shape, sliding about a hollow cylinder (6) which is vented to ambient air (8) at one end, but closed at its other end by a flap-type check valve (9). Upon downward movement of the plunger element, for example under electromagnetic force of a solenoid (2), air can flow freely from the vent opening (8) into the hollow interior and through the then open check valve (9); upon return movement under force of a spring (11), the flap valve (9) will close, however, thus forming an air cushion or air damper and preventing rapid, uncontrolled return of the plunger element to rest position, due to an air throttling path (19) between the outside of the hollow cylinder and the inner surface of the plunger element (4), said air throttling path being defined by the operating clearance between the plunger (4) and the hollow cylinder (6). The hollow cylinder (6) may be constructed as a guide element, unitary with the valve, and made of plastic, the valve being secured by a living hinge to the remainder of the hollow cylinder.
摘要:
A planing tool has a cylindrical body with elongated axially extending grooves in which elongated inserts with planing members are received, adjusting screws extending in a radial direction and arranged to adjust the radial distance of the inserts from the axis of rotation of the body, clamping screws arranged to clamp the inserts in the elongated grooves, wherein each adjusting screws extends through an opening of the respective insert with play, and a spring element is located between a bottom wall of each of the grooves and a respective one of the inserts.
摘要:
The power driven, hand operated plane of the type having a fixed front guiding plate adjoining the circular path of movement of the planing knife, and a vertically adjustable rear guiding plate controlled by an adjustment device assembled of a control disk mounted at one end of a screw spindle and projecting partially from the housing; the other end of the spindle engages a nut which is secured to the shoe by a preadjustment mechanism; a biasing spring presses the shoe against the nut; a dial provided on top of the control disk is visible to the user through a window in the housing.
摘要:
To reduce noise and idling speed of electric motors, particularly series motors, the speed-torque characteristic of the motor is dropped with respect to the loaded speed-torque characteristic, by sensing no-load operation of the motor and deriving a sensed signal, the sensed signal being applied to controlled switches to abruptly change the effective voltage applied to the motor between values corresponding to the no-load speed-torque characteristic, or the load speed-torque characteristic and resulting in the desired speed, in dependence on the value of the sensed signal. Preferably, the operating condition of the motor is sensed by an inductive transducer, and a speed change is obtained by phase control, or half-wave rectification.
摘要:
To detect if a tool bit, such as a drill, a saw blade, or the like, upon being worked into a wall, meets a metallic obstruction, such as a conduit, reinforcement rod, hydraulic pipe or the like, an alternating voltage, preferably between 2 and 20 kHz, is coupled through a coupling capacitor (9) to the tool bit, and current flow to the tool bit is detected by a current measurement stage (10; 31, 32) to disconnect energy to the drive motor (5), for example by disabling firing of a thyristor (15), or closing a valve of a compressed-air tool. The coupling capacitor should have a capacity small enough to provide high impedance to network power frequency, and to insure a substantial change in current being supplied to the tool bit holder, typically a chuck, if the tool bit meets a metallic object in the wall. The a-c supply circuit can be formed as part of a trigger circuit for the thyristor, by pulse-energizing a trigger diode (28) upon repetitive charge of a capacitor (26) through a charging network (22, 23, 24, 25).
摘要:
A hand-held power tool with a circular-disk-shaped tool mounted on an output shaft which extends normal to a drive shaft has a guiding part which surrounds the tool in an immovable position at its cutting side. The guiding part has a wall arranged for abutting against a workpiece and having a through slot for the tool, and a guiding edge extending parallel to a cutting direction of the tool, and the guiding part being movably guided in direction normal to the wall.
摘要:
A protecting hood assembly for use in a motor-driven hand tool such as grinder or circular saw. The assembly includes a hood having a pair of openings, each being formed with a narrowing portion of a squared cross-section and a widened portion forming a slot, a pair of vertically positioned supporting members each having a longitudinal slit and a couple of bolts having each a peripheral portion inserted into said slit and said opening. The widened portion of the opening receiving the bolt is formed with a size in a horizontal direction being larger that a diameter of the peripheral portion of the bolt and a size in a vertical direction being smaller that said diameter to facilitate the installation of the bolt into the hood opening upon assembling and to provide a reliable clamping of said bolt in assembly after insertion thereof.
摘要:
A mechanical switch is provided which, in a first position connects a current limiting circuit to a motor and, in a second position, disconnects the current limiting circuit from the motor. Mechanical activators are provided for the mechanical switch, to switch it from the first to the second position when the tool including the motor has a predetermined relationship to the workpiece. The mechanical activators provided for the mechanical switch operate the switch either when correct positioning of the tool relative to the workpiece results in a predetermined force being applied to the activator by the workpiece or when a shaft of the tool transmits a predetermined torque.
摘要:
To permit reliable turn-OFF of the motor when the torque of the motor is sufficient to provide for reliable seating of a screw or nut being driven thereby, start conditions of the motor are sensed, either in form of low-current condition or high power factor; high-torque conditions are sensed by low power factor, or high-current, in dependence on the desired torque level which results, respectively, in a comparatively steep phase angle-torque or current level-torque curve. A switch control is energized to turn-OFF the motor current if the phase angles, or the motor current, respectively, are beyond predetermined levels. To prevent in-rush current, or high power factors from affecting the operation of the turn-OFF system, timing circuits are provided to disable the turn-OFF system when the motor is first turned-ON or if the phase angle difference, as determined by time-comparator networks, between current and voltage, is below a predetermined value. Timing duration of at least one of the timing circuits can be controlled as a function of motor temperature to provide for linear response of the system, regardless of changes of motor operating parameter versus torque characteristics under varying motor temperature conditions.