Abstract: An attachment monitoring system according to an embodiment includes a working machine, attachments, a measurement unit, a terminal device, and a server device. The working machine includes a working arm. Each of the attachments is attached to a leading end part of the working arm so as to be driven by a fluid pressure. The measurement unit is provided to measure at least one of a vibration and the fluid pressure when each of the attachments identified on the basis of individual identifying information is driven. The terminal device is provided in the working machine to acquire measured results of the measurement unit. The server device collects the measured results of the respective attachments from the terminal device, and analyzes operation states of the respective attachments on the basis of the collected measured results.

Abstract: A pneumatic impulse wrench includes a housing with a motor powered impulse unit, a pressure air inlet passage, an exhaust air outlet passage located in the housing and connected to the motor, and a motor power controlling valve mechanism located in the exhaust air outlet passage for automatic control of the exhaust air flow from the motor. A control pressure passage extends between the air inlet passage and the valve mechanism for communicating actual air inlet pressure to the valve mechanism. An operating mode shifting valve is provided in the housing and which is shiftable between an open position in which communication is allowed through the control pressure passage in an automatic valve mechanism operating mode, and a closed position in which communication through the control pressure passage is blocked in a manual valve mechanism operating mode.

Abstract: A power tool includes a housing, a motor received in the housing, an output driven by the motor, and a control system. The control system includes a rotational motion sensor configured to generate a rotational motion signal that corresponds to a rotational motion of the housing about an axis, a current sensor configured to generate a motor current signal that corresponds to an amount of current drawn by the motor, and a control circuit that is configured to receive the rotational motion signal and the motor current signal and to control operation of the motor. The control circuit is configured: (a) to determine, based on the current signal, whether a detected kickback condition is likely to be false; (b) to determine, based upon the rotational motion signal, whether an uncontrolled kickback condition has occurred; and (c) to initiate one or more protective operations upon determining that an uncontrolled kickback condition has occurred and is not likely to be false.

Abstract: A handheld power tool including at least one drive unit, includes at least one oscillating excitation actuator for the oscillating drive of an associated insertion tool and includes an electronics unit for the controlled energy supply of the drive unit, the electronics unit including at least one inverter, one transformer, and one measuring circuit, the inverter being configured to generate a primary-side transformer voltage and a primary-side transformer current of the transformer, the transformer being configured to transform the primary-side transformer voltage and the primary-side transformer current into an application-specific supply voltage and a supply current for the drive unit, and a controller being associated with the measuring circuit, which is configured to generate at least one control signal for the inverter from a predefined setpoint value and a measured value detected by the measuring circuit, the measuring circuit is situated between the inverter and the transformer.

Abstract: Two 18V-type rechargeable batteries (31 and 31) are attached in series so as to allow a 36V-type tabletop cutting device (C1) to be utilized. By utilizing the 18V batteries which are highly prevalent for electric tools, it is possible to use the 36V-type tabletop cutting device (C1) as well as to reduce costs for the batteries.

Abstract: An apparatus including an accumulator and a drive mechanism. The accumulator includes an energy storage apparatus with a first piston face configured to reversibly compress an energy storage medium and a second piston face forming at least part of an inner surface of a corresponding second fluid chamber reversibly expandable by movement of the second piston face. A third piston face forms at least part of an inner surface of a corresponding third fluid chamber reversibly expandable by the third piston face. The first, second and third piston faces are coupled together.

Abstract: A wedge anchor driver for driving an anchor having a bolt into a surface such that a portion of the bolt is exposed, the wedge anchor driver having a flute extending between a top end and a shaft, the flute housing a plurality of cavities having a first cavity configured to fit onto a first nut, the first cavity having a first socket size; a second cavity configured to fit onto a second nut, the second cavity having a second socket size smaller than the first socket size; and a third cavity configured to receive the portion of the bolt; wherein the anchor driver shaft is lockable into a hammer drill, such that a user can drive the anchor into a corresponding hole with the hammer drill in a hammer mode, and then tighten the first nut or the second nut by switching the hammer to a drill mode.

Abstract: A system and method detect at least one mechanical locking position of a drill string in a soil drilling machine. According the system and method, there are: a sensor apparatus which is configured to detect first data indicating the position assumed by the top of the drill string and second data indicating the position assumed by the bottom of the drill string. A control unit calculates the estimated length of the drill string based on the data and to compare the estimated length with a reference length value. A pair of kelly rods is in a mechanical locking position; and a signaling apparatus is configured to signal when the estimated length corresponds to a reference length value.

Abstract: Electrically powered crimp tools are described. Also described are methods of operating the tools and methods of crimping. The tools include a housing, an electric motor, a roller screw assembly, and a jaw assembly. In particular versions of the tools the jaw assembly includes a cam linkage member that is manually displaced by a user to more easily open the jaws after performing a crimp.

Abstract: Disclosed combination impact tool generates optimized linear hammering and vibrational impacts. Flow of pressurized fluid through an upper section of the tool generates linear hammering impacts, and flow of pressurized fluid through a lower section of the tool generates vibrational impacts. Flow of pressurized fluid through the lower section induces an eccentric arm to rotate and cause vibrational impacts. While frequency of hammering impacts can be controlled by varying pressure of the fluid flowing through the upper section, the frequency and amplitude of vibrational impacts can be controlled by varying weight of the eccentric arm and by varying pressure of the fluid flowing through lower section.

Abstract: A pile measuring system suitable for determining parameter(s) of a pile during an installation of the pile is disclosed. The pile measuring system comprises at least one positioning sensor and a parameter calculator. Each of the at least one positioning sensor is attached or attachable to a location on a sleeve and configured to measure position coordinates of the respective location on the sleeve. The parameter calculator is suitable for determining the parameter(s) of the pile from the position coordinates measured by the at least one positioning sensor.

Abstract: Thresholds can be assigned for one or more parameters in connection with the operation of a surgical device. An ultimate threshold can trigger a desired action, including cessation of operations or modification of operations, if the ultimate threshold is reached, or predicted to be reached. In addition, a marginal threshold can trigger a desired action, including improving operations such as slowing operations where the value of a parameter is measured to be between the values defined by a marginal threshold and an ultimate threshold. Multiple thresholds, based on multiple parameters, can be defined, further enabling calibrated usage, such as slowing operations based on exceeding both a marginal threshold based on number of sterilization cycles and exceeding a marginal threshold based on extent to which current draw exceeds a certain value.

Abstract: A surgical instrument for use with a staple cartridge removably storing a plurality of staples is disclosed. The surgical instrument comprises a handle, a firing actuator operably coupled to the handle, a closure drive configured to selectively generate a closing motion and an opening motion, a firing drive configured to selectively generate a rotary firing motion upon actuation of the firing actuator, and an elongate shaft assembly operably coupled to the closure drive and the firing drive to separately transmit the closing motion before the rotary firing motion, and an end effector responsive to the closing motion. The end effector comprises a staple cartridge, an anvil, a cutting member movable relative to the staple cartridge in response to the rotary firing motion from the elongate shaft assembly, and an I-beam configured to control spacing between the anvil and the staple cartridge during deployment of the staples.

Abstract: There is provided an electric power tool having a plurality of operation modes with different rotation speeds at least in a predetermined load range. The electric power tool is capable of switching between the operation modes when a predetermined condition is satisfied even during a motor is driven, and configured such that a rotation speed of the motor is changed smoothly or in a stepwise manner at the switching between the operation modes.

Abstract: An electric chainsaw includes a first handle having a grip portion that is provided with a trigger switch for activating an electric motor. The electric chainsaw includes a second handle having a laterally extending grip portion provided forward of the grip portion of the first handle. The electric chainsaw includes an indicator lamp for indicating a remaining charge amount of a battery pack, and a push-button type indicator switch for causing the indicator lamp to indicate the remaining charge amount. The indicator switch is provided at a position where the worker can operate the indicator switch by a finger of the other hand gripping the grip portion of the second handle.

Abstract: A down the hole hammer (10) incorporates: an inner tube assembly (100); a fluid flow control system (200); a bit retaining system (400); a porting sleeve (600); and a piston (700). Each of the: inner tube assembly (100); fluid flow control system (200); bit retaining system (400); porting sleeve (600); and piston (700) in their own right provide benefit to the overall operation and/or reliability of the hammer (10).

Abstract: A cutting device for machines for cutting hides and the like, including an oscillating piston provided at its end with a cutting blade, the oscillating piston being actuated pneumatically by way of an inlet and an outlet, an oscillation chamber being defined by the lower and upper stroke limits of the oscillating piston, the device including a supply duct that leads to the oscillation chamber, the supply duct being regulated by a solenoid valve in order to raise the oscillating piston and consequently raise the cutting blade.

Abstract: A surgical instrument includes a shaft assembly, a handle assembly including a battery dock, and a battery unit. The battery unit is configured to be received by the battery dock such that the battery unit is in electrical communication with at least one of the shaft assembly or the handle assembly. The battery unit includes a casing, an anode contact and a cathode contact within the casing, and a discharge drain. The discharge drain includes a controller, a switch element, and a resistor element operatively connected between the cathode contact and the anode contact. The controller is configured to selectively direct the switch element to close such that the resistor element is in electrical communication with the anode contact and the cathode contact. Thereby, the resistor element is configured to drain a remaining electrical power from the at least one battery connected to the anode contact and the cathode contact.

Abstract: A trolley for use with a fall arrest system, the trolley providing active control of both downward movement of a body attached to a rope or cable and horizontal position along a track.

Abstract: A pump jack controller is provided that can harness the waste energy generated during the operation of a pump jack when its electrical motor is in an over-speed condition, and convert that waste energy into electrical energy that can be supplied back onto an electrical power grid thus converting the pump jack into a micro electric power generator.

Abstract: A method of compacting soil via a base machine, the base machine having ram material provided at at least one cable and having a regulation/control apparatus, includes raising the ram material from the land area to be compacted, with a zero point being stored at which no slackline is present. The method further includes raising the ram material to a lift height, carrying out a compaction procedure by dropping the ram material from a drop height onto the land area to be compacted, again raising the ram material from the land area to be compacted, with a further zero point being stored at which no slackline is present, determining and storing a compaction progress, and repeating the previous steps until the compaction progresses of each of a predefined number of consecutive compaction procedures are smaller than or equal to a predefined minimum progress.

Abstract: A rechargeable battery pack can provide power to a device that also accepts at least one standard non-rechargeable battery. The rechargeable battery pack may include a housing for housing at least one battery cell and recharging circuitry. The at least one battery cell and the recharging circuitry can be housed substantially within the housing. The recharging circuitry can be coupled with the at least one battery cell. The recharging circuitry can be configured to charge the at least one battery cell when the battery pack is inserted into the device that also accepts at least one non-rechargeable battery. The rechargeable battery pack may further include a protection circuit coupled with the recharging circuitry.

Abstract: A power tool with a chuck and a tool body having a housing, a motor received in the housing, a light array mounted to the housing, and an output spindle extending through the light array and which is rotationally driven by the motor. The chuck has a chuck body, a plurality of jaws, and an outer sleeve. A rear end of the chuck body is rotatably mounted on the output spindle. The chuck body has a plurality of jaw apertures and a plurality of light holes. The jaw apertures and the light holes extend through a front surface of the chuck body. Each of the jaws is received in a corresponding one of the jaw apertures. The outer sleeve is disposed about the jaws and the chuck body. Light emanating from the light array is transmitted through the light holes to illuminate a zone in front of the chuck body.

Abstract: In a surgical power tool that includes an electric motor positioned in a housing and a movable element extending from the housing and operatively actuated by the electric motor, a controller can repeatedly interrogate for faults a plurality of components in or on the housing, such as the electric motor, the controller, a battery, a trigger, and a mode switch. Upon finding a component in a fault condition, the controller can engage a critical error handler that disengages the electric motor, disables at least some of the plurality of components, and directs a microprocessor in the controller into a safe software state. Upon engaging the critical error handler, the controller can further write to a memory an error code corresponding to which of the plurality of components is in the fault condition. The error code can be accessible via a wired or wireless connection.

Abstract: A method to control a power tool including the method steps: specifying the rotational speed of the drive at a first value, measuring a first amplitude of a signal, filtering the signal within a frequency range, measuring a second amplitude of the filtered signal, reducing the rotational speed of the drive to a second value if the first amplitude exceeds a first quantity and if the second amplitude exceeds a second quantity, and incrementally increasing the rotational speed of the drive to the first value, whereby each incremental increase of the rotational speed only takes place once the first amplitude remains below the first quantity for a time interval, and the second amplitude remains below the second quantity. A power tool that uses this method, includes: a drive, an acceleration sensor a filter, and a control unit.

Abstract: An operation switch sends an ON signal to a control processor indicating the operation switch is triggered by a user. A magnetic sensor sends a sensor signal to the control processor based on a displacement of a chip rod in a rearward direction. In the case where the sensor signal has not yet been sent, the control processor performs a control in a first mode where a brushless DC motor is not driven. In the case where sensor signal is sent, control processor performs a control in a second mode wherein the brushless DC motor is driven. An output in the first mode is lower than in the second mode. Because of this manner of construction, even if an ON input is triggered and held by the user, electric power is conserved while the operation switch is switched on and a hexagonal nut is not fastened, improving power consumption efficiency.

Abstract: Powered drivers, and kits and methods including or using powered drivers, having a driveshaft extending from a distal end of the housing and configured to slide responsive to a force applied to a distal end of the driveshaft and activate a motor to rotate the driveshaft. Some of the present powered drivers include a housing having a distal end and a proximal end; a motor disposed in the housing; a driveshaft extending outward from the distal end of the housing (e.g.

Abstract: A control method according to an aspect of the invention includes a process for setting target fastening torque, a pulse interval of neighboring pulses, and an elevated value of torque per pulse, detecting last fastening torque at an Nth pulse (N is a natural number of 1 or more) after seating of a fastening member, setting pulse loading time at an N+1th pulse and pulse strength at the N+1th pulse based on the last fastening torque at the Nth pulse so that fastening torque at the N+1th pulse coincides with a multiple of the elevated value, controlling a fastening tool based on the pulse interval, the pulse loading time, and the pulse strength so that last fastening torque at an N+Mth pulse (M is a natural number of 1 or more) reaches target fastening torque.

Abstract: A cable drum assembly may comprise a shaft configured to rotate about an axis. A drum may be positioned radially outward from the shaft and configured to rotate about the axis. A ball spline may be in operable communication with the shaft and the drum, the ball spline disposed between the shaft and the drum and configured to orbit the axis.

Abstract: The present invention relates to a impact body for a hydraulic impact device and, more specifically, to a impact body for a hydraulic impact device which is capable of remarkably reducing production costs by inserting a cylinder liner having a flow path into an inner wall of a body, adjusting an impact interval and an impact strength according to the properties of a material to be crushed by adjusting an impact distance of a piston, minimizing the loss of a fluid in a pipe by forming a cylindrical flow path between the body and the cylinder liner, and remarkably improving performance by employing a circular valve to shorten the flow path whereby reduction of pressure is minimized.

Abstract: A tightening tool such as a torque wrench is provided in which electric power can be fed to an electronic circuit with eliminating the need for a battery and achieving daily maintenance-free. In the tightening tool, when a tightening torque has reached a set torque value and a torque limiter is actuated, an electronic circuit unit that has obtained a detection signal outputted from a torque limiter actuation detection unit outputs a tightening completion signal. The tightening tool has a power generation unit for feeding electric power to the electronic circuit unit at least during the actuation of the torque limiter. The power generation unit performs photovoltaic power generation, electromagnetic induction power generation, power generation by conversion from mechanical energy into electrical energy, or temperature difference power generation.

Abstract: An electrical switch, particularly for an electrical appliance having an electric motor. The switch has two electrical supply connections for the supply voltage, particularly for a rechargeable battery, and two electrical motor connections for the supply of voltage to the electric motor. Furthermore, the switch has a control electronics unit, such as a microprocessor, a microcontroller or the like, for executing control processes in the electrical appliance, wherein particularly the control electronics unit operates by means of a piece of software. The switch can also be connected with a data line for communication between the control electronics unit and an external device, wherein particularly one of the electrical motor connections is used as an interface for the data line. Furthermore, the invention relates to an appropriate method for communication by an electrical switch with an external device.

Abstract: A ram boring device has a pressurized-fluid driven striking piston in a device housing and a rotating reversing device configured to urge the striking piston from a forward operation to a reverse operation, in order to create oblique or horizontal bores in the ground. A piston chamber of a rotary piston drive is connected to a control fluid line.

Abstract: A motor driving device comprises a first heat sink arranged outside a housing, a second heat sink arranged inside the housing, and a heat conduction plate configured to thermally connect the first heat sink and the second heat sink. A switching element for a spindle is mounted on the first heat sink, and a switching element for a feed axis is mounted on the second heat sink.

Abstract: A vibrator-system for sinking an object into the ground by means of vibration, comprises a suspension yoke, a carter or carters mounted to the suspension yoke and equipped with a rotatable eccentric weight or weights for the generation of the vibration, and clamping means connected at a side of the carter or carters that is opposite to the suspension yoke for clamping the object, wherein the vibrator system is convertible between a first configuration and a second configuration, wherein in the first configuration a single carter is mounted to the suspension yoke and the clamping means are mounted to the single carter, and that in the second configuration two carters, each equipped with a rotatable eccentric weight or weights, are mounted between the suspension yoke and the clamping means.

Abstract: Disclosed combination impact tool generates optimized linear hammering and vibrational impacts. Flow of pressurized fluid through an upper section of the tool generates linear hammering impacts, and flow of pressurized fluid through a lower section of the tool generates vibrational impacts. Flow of pressurized fluid through the lower section induces an eccentric arm to rotate and cause vibrational impacts. While frequency of hammering impacts can be controlled by varying pressure of the fluid flowing through the upper section, the frequency and amplitude of vibrational impacts can be controlled by varying weight of the eccentric arm and by varying pressure of the fluid flowing through lower section. Disclosed tool is particularly useful in drilling in shale and in fishing operations in a well-bore.

Abstract: A tool, such as a pneumatic tool, having a first and second housing portions coupled together. The first housing portion including an upper portion adapted to receive power and transmission components and a handle portion including a recess adapted to receive a trigger assembly. A reinforcement member is disposed in the recess with a first side facing in a first direction away from the recess and towards the second housing portion, and a protrusion extending from the first side in the first direction. The protrusion engages the second housing portion and strengthens the handle portion to allow the handle portion to withstand forces resulting from the tool being dropped on a hard surface.

Abstract: A fastener installation tool and related method are provided for installing fasteners in boards. The tool can include a feed mechanism that automatically and sequentially feeds collated fasteners to a nose assembly. The nose assembly can include a guide having an alignment projection extending downwardly from the guide, and configured to engage a board corner and/or side surface, so as to align an angled bore through which fasteners are guided with the board corner and or side surface. The nose assembly can include a magnetic element located adjacent a path on which the collated fasteners are advanced. The magnetic element can exert a magnetic force on an individual fastener, aligning it for precise entry into the angled bore. The nose assembly can include a guide pocket to positively constrain a fastener as it rotates to ensure a desired advancement trajectory. A related method of installation is provided.

Abstract: A medical or dental fluid-driven handle with a control or regulation circuit for the control or regulation of the rotational speed of a rotary part to a predetermined rotational speed and methods are presented. The handle comprises a rotary part that can be set in rotary motion by a drive fluid, a fluid line carrying the drive fluid to or from the rotary part or a fluid branch line that is connected to a fluid line carrying the drive fluid, and a control or regulation circuit that is designed to control or regulate the rotational speed of the rotary part. An electrodynamic converter is driven by the rotary part for generating electrical energy. An actuator element is configured to act on the drive fluid and is electrically connected to the electrodynamic converter such that the actuator element is supplied with electrical energy generated by the electrodynamic converter.

Abstract: A power tool with a combined printed circuit board (PCB) that reduces internal wiring of the power tool and provides a large amount of air flow to internal components. In some instances, the combined PCB has a surfboard shape and includes a motor control unit and power switching elements (Field Effect Transistors or FETs). The combined surfboard PCB is located above the trigger, but below the motor and drive mechanism. In other instances, the combined PCB has a doughnut shape and is located coaxially with a motor shaft. The combined PCB may be positioned between a doughnut-shaped control PCB and the motor.

Abstract: A tightening device is able to check that a fastening member has been fastened to a desired set torque or greater after being tightened, without loosening the fastening member.

Abstract: An electric power wrench for fastening and loosening joints includes: a main shaft for delivering a torque to a joint, an electric motor that is arranged to selectively drive the main shaft in two opposed rotational directions, a control unit for controlling the drive of the electric motor, and a transmission that connects the electric motor to the main shaft. The control unit has a first drive mode in which it controls the electric motor such that it delivers a continuous torque in a forward direction, and delivers torque pulses in an opposite backward direction, wherein the transmission includes an inherent play and wherein the torque pulses are produced in said play.

Abstract: A device for magnetizing laser plasma by unit of a pulsed magnetic field, which includes: a laser source for emitting a laser pulse; a vacuum chamber in which a target capable of generating a laser plasma during an interaction of the laser pulse with the target is arranged; and a coil capable of generating a pulsed magnetic field in the laser plasma, the device being characterised in that the coil is arranged in a reentrant chamber containing a coolant.

Abstract: A method of installing a plurality of pin piles into a seabed including at least the steps of: (a) lowering a pin pile apparatus comprising a first pin pile and an attached clump weight towards the seabed; (b) allowing the first pin pile to self-penetrate the seabed based on self-weight of the pin pile apparatus and the momentum from step (a) until the clump weight reaches the sea bed; (c) disconnecting the clump weight from the first pin pile; and (d) recovering the clump weight for use with a second pin pile and repeating steps (a)-(c). In this way, the pin piles are easily installed from their descent to the seabed with the clump weight, which can then be removed and applied to the next pin pile in an easy and repeatable operation without requiring a suction apparatus or hammer or drill.

Abstract: A system for preloading a fastener of a mechanical fitting includes a strain measuring device to measure a strain on the fastener as the fastener is tightened. The mechanical fitting may include a base structure and a plate member. A support structure supports the plate member at a predetermined spacing from the base structure. The support structure may include a first sloping plate and a second sloping plate each extending between the plate member and the base structure. The fastener extends through a first hole in the plate member and a second hole in the base structure. The fastener is accessible through an opening on each side of the support structure. At least a portion of the strain measuring device is positioned relative to the fastener through a first opening of the openings to measure the strain on the fastener correlating to the preload as the fastener is tightened.

Abstract: A method for controlling a torque output of a DC electric tool, includes presetting torque levels and voltage ranges corresponding to the torque levels, detecting the current output voltage of a battery and determining the voltage range in which the current output voltage is located, determining whether or not the current voltage range matches the preset torque level or not, and if the current voltage range does not match the preset torque level providing a warning that the torque output cannot reach the preset torque level and calculating and displaying a maximum torque level corresponding to the actual torque output value and, if the current voltage range does match the preset torque level, calculating the current actual torque output value and keeping a PWM modulation value constant if the torque output value conforms to the preset torque level or increasing the PWM modulation value for compensation if the torque output value does not conform to the preset torque level.

Abstract: A power tool comprises a driving mechanism and a gear housing space (105a) which houses the driving mechanism. A lubricant is provided to the driving mechanism inside a gear housing (105). The driving mechanism includes a driving motor (110) having a motor shaft (111). The motor shaft (111) includes an inner communicating opening (191), an outer communicating opening (192) and an air passage (193) which connects the inner communicating opening (191) and the outer communicating opening (192). At least a part of the air passage (193) is arranged inside the motor shaft (111), and the passage (193) communicates with the gear housing space (105a) via the inner communicating opening (191) and also communicates with the outer space of the gear housing (105) via the outer communicating opening (192).

Abstract: A power tool includes a housing, a motor, an output member driven by the motor, and a reaming attachment coupled to the output member. The reaming attachment has a front end portion selectively driven in rotation by the output member to drive a fastener into a workpiece, and a reaming portion selectively driven in rotation by the output member to remove material from an end surface of a conduit. A rotational motion sensor in the housing is operable to detect rotational motion of the housing about an axis. A controller receives a signal indicative of rotational motion from the sensor, determines a direction of the rotational motion of the housing, and drives the motor in a direction corresponding to the direction of rotational motion of the housing.

Abstract: The disclosure relates to a mining vehicle and a method of moving a boom of a mining vehicle. The boom is provided with several boom joints and there is a mining work device at a distal end of the boom. One or more boom joint positions are determined and stored in a memory medium. A control unit of the mining vehicle may automatically move the boom to a predetermined transport position.

Abstract: A follower assembly includes a follower mounted on an axle with the axle being coupled to a carrier that is pivotable relative to the frame about a pivot axis. The follower assembly has a locked position in which the pivot axis and axle are positioned relative to each other in a locked over-center position. In the locked over-center position the driver is pinched between the follower assembly and the flywheel subjecting the driver to a pinch force when the driver is in the stall position. When the driver is in the stall position and the follower assembly is in the locked over-center position, pivotal movement of a stall release lever toward the release position forces the follower assembly out of the locked over-center position toward the reverse over-center position in which the relative positions of the pivot axis and axle are reversed and the pinch force is released.