Abstract: A safety control circuit for a direct current electromotive nail driver comprises: a direct current power source for supplying power to the circuit; a control and protecting unit having a security switch, a trigger switch and a stop switch; and a motor for driving an object. When the security switch is turned on and then the trigger switch is pressed, the control and protecting unit will receive a signal from the trigger switch so as to conduct the motor and thus the motor operates to drive an object. When the motor operates through a predetermined time period, the stop switch will actuate a protection function of the control and protecting unit so that the motor cannot operate until the security switch is actuated again.

Abstract: The present invention is directed to a combustion-operated setting device for driving fastening elements such as nails, bolts and pins into a substrate, with a setting mechanism comprising a driving piston (15) which is supported to be displaceable in a guide, and with an electronic monitoring device for monitoring the status of the setting device. At least one sensor array (21, 22) is arranged at the guide for generating a measurement data pattern which can be evaluated by the monitoring device.

Abstract: The present invention is to provide a staple cartridge that can offset any discrepancies when mounting a staple cartridge, even if staples are slightly offset to check the occurrence of stapling defects. The staple cartridge 100 of the holding means 200 which is equivalent to the cartridge holder disposed as either a body separate to the stapler unit 300 or unitized thereto, actuates the staple feeds means 202. Even if the position of the staple pulled out from the staple cartridge is offset, this action corrects the offset to correctly set the staple at the driving position thereby enabling it to check stapling defects that occur because of mis-positioning of the staple set position.

Abstract: A staple storage unit includes return prevention members that prevent a staple positioned for driving from moving back toward the staple storage portion of the staple storage unit. A plurality of staple abutting portions 105a and 105b are spaced along the draw out direction of the staple band 101 at distances where they do not all abut the staple linking portion 105d, thereby increasing the likelihood that at least one of the staple abutting portions will engage the staple linking portion to prevent significant withdrawal of the staple sheet back toward the staple storage portion.

Abstract: A stapler apparatus of the type using continuous belt-formed staples 200 includes a staple feed claw 25 for advancing the staples 200 sequentially to a stapling position 103, and a drive means 50 for driving the staples 200 drawn to the stapling position 103. A clincher means 40 bends the ends of the staples 200 driven into the sheets and pivots a staple feed pawl 25 interlocked to the staple bending operation of the clincher means 40 for sequentially feeding the staples 200 to the stapling position 103. This construction lightens the load on the drive means to staple sheet stacks, facilitates smooth driving operation of the drive means, and reduces the occurrences of trouble.

Abstract: A stapler apparatus includes a fixed frame, a movable frame pivotably mounted to the fixed frame, a staple driving device, and a staple bending device to bend the staples. A drive mechanism reciprocally moves the movable frame with respect to the fixed frame to clamp a stack of sheets between the fixed frame and the movable frame. A transmission member is movably supported on the movable frame without any connection utilizing an elongated slot. An urging member is disposed to bias the transmission member with respect to the movable frame, the transmission member being coupled to the drive mechanism such that the drive mechanism engages and moves the transmission member with respect to the movable frame, thereby overcoming the bias of the urging member, to compensate for a stack height of the stack of sheets clamped between the fixed frame and the movable frame.

Abstract: A stapler apparatus includes right and left side frames each opposing the other, a reciprocally moving staple driving member arranged between the side frames, a cam member interlocked to the staple driving member to reciprocally move the staple driving member and a drive motor interlocked to the cam member. The drive motor, the cam member and the staple driving member are arranged in order between the left and right frames.

Abstract: The present invention relates to a safety switch for an electric nailer including a trigger which can return to original state after being pressed. The safety switch comprises a stop portion and a safety member, the stop portion is formed in the electric nailer. The safety member includes a push plate and an abutting portion, and the safety member is fixed in the electric nailer and can return to its original position after being pressed, the push plate serves to cover the trigger, and the abutting portion abuts against the stop portion. Thus, the electric nailer will be in a safe mode automatically when not in use, and an accident of pressing the trigger by mistake can be prevented.

Abstract: A cartridge comprises a container 11 for housing a connected staple, a driving section 21 for driving a staple, a conveying path 25 which extends from the container 11 to the driving section 21, and conveys the connected staple, a feeding member 30 which is disposed in a position remote from a guide member 23 forming the conveying path 25, and reciprocates along the conveying path, feeding claws 31A, 31B having leading end portions which are attached to the feeding member 30, and project in the conveying path 25 from openings 23A, 23B formed in the guide wall 23, and the connected staple being fed toward the driving section 21 by the feeding claws 31A, 31B when the feeding member 30 advances. The cartridge further comprises a link mechanism 50 for moving the feeding member 30 backward when a lid 13 of the container 11 is opened.

Abstract: A handy electric nailing gun includes a firing pin, a firing spring for pushing the firing pin to drive nails into workpiece, an output gear rotatable by a motor through a transmission gear set to retract the firing pin during the first half run of each rotation cycle and to release the firing pin during the second half run of each rotation cycle, and three power switches electrically connected in series between the motor and the power source (AC adapter/rechargeable battery) for operation by the user to control the operation of the motor.

Abstract: A stapler apparatus includes a cartridge that stores staples, a staple driving unit for engaging and driving staples, an urging member to urge the cartridge toward the staple driving unit, and an interlocking mechanism movable upon installation of the cartridge to apply the urging member to the cartridge. The construction provides a stapler apparatus that allows the easy mounting of a cartridge and that can effectively urge a cartridge toward the punching station of the stapler.

Abstract: A control module advantageously reduces cost and enhances reliability, design flexibility, ease of assembly, and performance of a flywheel operated hand tool. The control module includes a thin film printed circuit with non-contact speed sensing of a flywheel to more accurately set the target speed and control transfer kinetic energy thereof to a fastener, achieving a desired depth regardless of variations in component performance and battery voltage. The printed circuit also includes long service life thin film switches for responding to trigger and safety inputs. Furthermore, the control module responds to a user speed selection and to preset speed selection ranges to reconfigure the controls as appropriate to constraints of a fastener drive assembly and to user preferences.

Abstract: A fastening tool that drives a fastener into a work-piece. The tool includes a motor that is connected to a transmission. The transmission includes a flywheel. The tool also includes a driver mechanism that is adapted to drive the fastener into the work-piece. The flywheel is connected to the driver mechanism when the flywheel is in a flywheel firing position. The tool includes a control module that detects a flywheel position and compares the flywheel position to the flywheel firing position. The control module also adjusts the flywheel position based on the comparison. The control module ensures that the transmission has enough rotations to ensure that enough momentum can be generated to drive the fastener into the work-piece.

Abstract: An electric nailing gun is disclosed to use a sensor in the nail magazine and to connect the sensor to a control circuit such that when a magazine follower is moved to a predetermined position in the nail path, the sensor sends a control signal to the control circuit to drive a counter to start counting the number of striking actions of the plunger, and the control circuit controls the electric nailing gun to reduce the plunger impact when the counting of the counter reaches a predetermined value.

Abstract: A magnetically operated driving tool includes a body member, first and second stator magnets at opposed ends of the body with like poles facing one another, a movable magnet (traveler), a coupling adjacent each stator coupled to a user-operable linkage, a hammer, and a spring. In use, the traveler begins magnetically coupled to the first stator and engaged with the first coupling; the hammer holds a fastener. A user operates the linkage, rotating the traveler until its and the first stator's polarity match. The first stator magnetically repulses the traveler, which propels the hammer to insert the fastener and moves to the second stator where it engages the second coupling. The user operates the linkage, causing the traveler to rotate until its and the second stator's polarity match. The second stator then magnetically repulses the traveler, which engages the spring and reaches the first stator, returning to the initial configuration.

Abstract: A stapler apparatus includes a staple driving member to drive staples into a sheet bundle and being reciprocally supported on a frame. The staple driving member is configured to engage and drive staples. A cam member is interlocked to the staple driving member to reciprocally move the staple driving member. A drive motor is interlocked to the cam member. The cam member includes at least two rotating cams comprising rotating shafts extending in a direction intersecting a plane formed by said staple driving member reciprocal movement locus. The two rotating cams and the staple driving member abut at at least two points.

Abstract: A staple cartridge includes: a cartridge body for accommodating a large number of staples; and a face plate provided at a front end portion of the cartridge body, for forming a striking passage (211) of striking a staple by a driver, wherein support pieces are integrally formed from both side edges of the face plate to the rear, engaging bosses formed in the support pieces are engaged with recess portions formed on both sides of the front end portion of the cartridge body (206), and the face plate is slidably and pivotally supported by the cartridge body (206). In the cartridge body (206) and cover (209), the small thickness grooves (215), (216), by which the staple cartridge (204) is bent into two pieces, are formed on the circumference of the staple accommodating portion.

Abstract: A staple cartridge that sequentially draws out rolled staple band material from the staple storage portion includes regulating device that touches the stacked surface of the rolled staple band to regulate the widening and unraveling of the stacked surface. The regulating device is capable of regulating the widening of the stacked surface of the staple band material in the roll diameter direction even during vibration of the cartridge. This minimizes the phenomenon of the staple band material biting to or catching on the staple cartridge.

Abstract: A stapler apparatus is equipped with linked staples and includes a staple feed member configured for feeding staples to a driving position, a staple driver operable to drive the staples from the driving position into a stack of sheets, and an anvil unit operable to engage and clamp the stack of sheets to be stapled. The staple feed member is powered by movement of the anvil unit.

Abstract: A cartridge comprises a sheet staple detecting mechanism (60) for detecting presence and absence of sheet staples (ST) stacked on a bottom having an opening (23A). The sheet staple detecting mechanism (60) includes a detected member (30) having leg parts (32, 32, 33 and 33), which are disposed on the uppermost surface of the stacked sheet staples (ST) and configured to be inserted in the opening (23A) when the sheet staples (ST) are not disposed on the bottom (23), an actuator (40) rotated at the time the leg parts (32, 32, 33 and 33) are inserted in the opening (23 A), and a micro-switch (50) for detecting the rotation of the actuator (40).

Abstract: A staple cartridge which is composed in order to guide a leading end (20a) of a replacing roll staple (20) provided with a band (21) to a guide path (12) with pulling out a leading end of the band (21) from a front portion (11) of an operable and closable lid (2) to load the roll staple (20) and with rotating the roll staple (20) in a staple loading room (6) in a state in which the lid (2) is closed. Roll abutment portions (10) are arranged on the inner surface (2a) of the staple loading room (6), the roll staple (20) which is located between the roll abutment portions, are rotatably held by them striding an adhesive portion (A) to prevent a contact between the inner surface (2a) and an adhesive portion (A) which has an adhesive material.

Abstract: A driver unit comprises a fixed frame (12), an inner frame (20), a magazine (40), a cartridge (50), a driver (70) attached movably upwardly and downwardly to the magazine (40) and pivoted on the inner frame (20), and a basing member for biasing downwardly the magazine (40). A staple is driven out through the driver (70) entered in a drive-out part by the inner frame being moved upwardly together with the magazine (40) by the lifting of a clincher part (111) of a clincher unit (100). When the clincher part (111) is lowered, the inner frame (20) and magazine (40) are lowered and returned to an initial position by the biasing member. The magazine 40 is attached rotatably about a shaft 44 on the inner frame 20. The cartridge (50) can be removed from the magazine (40) by rotating the magazine (40) to direct upwardly a back portion of the magazine (40).

Abstract: In an electric stapler which includes: a passage (4) formed in a magazine portion (2) of the stapler body (1), for attaching and detaching a staple cartridge (3); and sheet staples (a) accommodated in the staple cartridge (3), wherein both side portions of the lead staple (a1) and the following staples of the sheet staples (a) are successively bent and stricken, a staple detection sensor (7), both sides of the end of the actuator (8) of are tapered, is arranged so that both side portions can be directed to an entrance of the passage (4) and the end of the staple detection sensor (7) can be engaged with an upper or a lower face of the sheet staples (a) of the staple cartridge (3) attached into the passage (4). The actuator (8) is swung and tilted in the perpendicular direction to the longitudinal direction of the passage (4) and biased by a spring so that it can obliquely rise at all times.

Abstract: An impact enhancing device of an electric nailer, comprising: an AC power source, a protection circuit, a first switch, a full-wave rectifier, a timing controller circuit, an energy-storage circuit, a solid-state switch circuit, an electro-magnetic coil device, a DC power source, a second switch, a reset enable single shot trigger circuit, and a relay. Thus, the electric nailer provides a larger impact force with a smaller volume and a lighter weight.

Abstract: A nail driving gun includes a gun housing, a solenoid mounted in the gun housing and including a coil member and a magnetic core which are magnetically attracted to each other in such a manner that the magnetic core is movable in a frontward direction and the coil member is movable in a rearward direction opposite to the frontward direction when the solenoid is actuated, a striking pin extending from the magnetic core so as to be movable together therewith and so as to expel a nail upon actuation of the solenoid, an urging member for restoring the magnetic core to a normal position, and a shock-absorbing member resiliently abutting against the coil member so as to provide a shock-absorbing effect on the nail driving gun.

Abstract: A stapling device includes a wire fed in the casing of the device and a staple-bending member is movably connected to a base in the casing and has two protrusions extending from a lower end thereof. An ejecting member movably connected to the base. A mechanism is driven by an activation member and lowers the staple-bending member and the ejecting member to deform a section of the metal wire to be a staple which is ejected through an aperture to staple a pile of document.

Abstract: An impact device (10) employing a novel direct electric propulsion system. The device operates by placing a conductive piston (23) adjacent to an electric coil (18) then rapidly releasing electrical energy stored in a capacitor (17) to energize the coil (18) and propel the piston according to the Lorentz force principal. The system can be designed for a wide range of drive energy, and offers several performance advantages over known propulsion systems. These advantages include simple construction and operation, low manufacturing costs, low drive energy variation, and the ability to adjust drive energy while over a wide range while maintaining low energy variation at reduced levels. The system is adaptable to be powered by either corded electric, or battery, or fuel cell.

Abstract: This invention provides a stapler apparatus that can recover the binding means securely to the idle position region for smooth binding, even if the binding speed is increased in accordance to the processing speed of the system apparatus that incorporates the binding speed of the stapler apparatus.

Abstract: A staple sheet-detecting mechanism of an electric stapler having its detection accuracy improved and realizing miniaturization thereof is disclosed.

Abstract: A portable electric nailing gun operating from a power supply. The motor accelerates a flywheel which at the appropriate energy state is coupled through a mechanism to an anvil acting directly on the nail. The actuation is governed by a control circuit and initiated from a trigger switch. The motor accelerates a flywheel that is then clutched to the output anvil causing the nail to be driven. The position of the output anvil is sensed and once the nail is driven, the motor is dynamically braked reducing the excess energy in the flywheel. This method uses an intermediate link in the drive train and a position sensitive nailing mechanism to reduce wear and increase robustness of the nailer. The electrical control circuit and brake allow precise control and improve safety. The power supply is preferably a rechargeable low impedance battery pack.

Abstract: An electric stapler capable of handling multiple sheets of paper. A motor-driven pair of wheel gears turn a swing arm having a symmetrical structure for driving a staple firing assembly and a clinch mechanism, thereby applying large pressure uniformly on staples. The clinch mechanism bends staple legs in different directions so that they do not overlap each other, preventing the clinched part of paper from increasing in the thickness of the stacked paper.

Abstract: A stapler is provided with a frame and a head assembly pivotally disposed in the frame between a first open position and a second clamped position. The head assembly contains all of the operative elements of the stapler necessary to carry out a stapling operation and is biased toward the open position by a biasing member disposed between the head assembly and the frame. These operative elements include a staple driving mechanism, a motor fixed to the head assembly, a cam member connected to the motor and rotated thereby. The cam member contains at least three surfaces that simultaneously form and drive staples, pivot the head assembly in the frame, and actuate a microswitch controlling power to the motor. The cam member cooperates with a first bar disposed between the frame and a spring assembly to permit the first bar to flex to accommodate varying thicknesses or amounts of paper to be stapled.

Abstract: A staple cartridge that sequentially draws out rolled staple band material from the staple storage portion includes regulating means that touches the stacked surface of the rolled staple band to regulate the widening and unraveling of the stacked surface. The regulating means is capable of regulating the widening of the stacked surface of the staple band material in the roll diameter direction even during vibration of the cartridge. This minimizes the phenomenon of the staple band material biting to or catching on the staple cartridge.

Abstract: A compact, lightweight and rechargeable electric stapler for automatically punching holes in documents and the like is provided wherein a fixed switch is fixed to the case body and an actuating bar is moveable at the front end and back end, so the switch is durable and also the presence of staples can be determined at a glance with a LED. The electric stapler comprises a case body, drive train, wiring board, magazine frame, an arm, a fixed switch wherein an actuating switch for actuating the drive train (motor) is mounted on the case body, and a moveable actuating bar coupled to the fixed switch and mounted between the case body and frame.

Abstract: A staple cartridge includes: a cartridge body for accommodating a large number of staples; and a face plate provided at a front end portion of the cartridge body, for forming a striking passage (211) of striking a staple by a driver, wherein support pieces are integrally formed from both side edges of the face plate to the rear, engaging bosses formed in the support pieces are engaged with recess portions formed on both sides of the front end portion of the cartridge body (206), and the face plate is slidably and pivotally supported by the cartridge body (206). In the cartridge body (206) and cover (209), the small thickness grooves (215), (216), by which the staple cartridge (204) is bent into two pieces, are formed on the circumference of the staple accommodating portion.

Abstract: A cartridge comprises a sheet staple detecting mechanism (60) for detecting presence and absence of sheet staples (ST) stacked on a bottom having an opening (23A). The sheet staple detecting mechanism (60) includes a detected member (30) having leg parts (32, 32, 33 and 33), which are disposed on the uppermost surface of the stacked sheet staples (ST) and configured to be inserted in the opening (23A) when the sheet staples (ST) are not disposed on the bottom (23), an actuator (40) rotated at the time the leg parts (32, 32, 33 and 33) are inserted in the opening (23 A), and a micro-switch (50) for detecting the rotation of the actuator (40).

Abstract: In an electric stapler which includes: a passage (4) formed in a magazine portion (2) of the stapler body (1), for attaching and detaching a staple cartridge (3); and sheet staples (a) accommodated in the staple cartridge (3), wherein both side portions of the lead staple (a1) and the following staples of the sheet staples (a) are successively bent and stricken, a staple detection sensor (7), both sides of the end of the actuator (8) of are tapered, is arranged so that both side portions can be directed to an entrance of the passage (4) and the end of the staple detection sensor (7) can be engaged with an upper or a lower face of the sheet staples (a) of the staple cartridge (3) attached into the passage (4). The actuator (8) is swung and tilted in the perpendicular direction to the longitudinal direction of the passage (4) and biased by a spring so that it can obliquely rise at all times.

Abstract: A driver unit comprises a fixed frame (12), an inner frame (20), a magazine (40), a cartridge (50), a driver (70) attached movably upwardly and downwardly to the magazine (40) and pivoted on the inner frame (20), and a basing member for biasing downwardly the magazine (40). A staple is driven out through the driver (70) entered in a drive-out part by the inner frame being moved upwardly together with the magazine (40) by the lifting of a clincher part (111) of a clincher unit (100). When the clincher part (111) is lowered, the inner frame (20) and magazine (40) are lowered and returned to an initial position by the biasing member. The magazine 40 is attached rotatably about a shaft 44 on the inner frame 20. The cartridge (50) can be removed from the magazine (40) by rotating the magazine (40) to direct upwardly a back portion of the magazine (40).

Abstract: A nail-hammering apparatus includes a hammer, a first solenoid, a second solenoid and a control device. The hammer can hammer a nail into a workpiece. The first solenoid can be turned on so as to drive the hammer. The second solenoid can be turned on in order to drive the hammer after the first solenoid. The spring tends to bias the hammer to its original position when the second solenoid is turned off. If the nail has not entirely enters the workpiece, the control device turns on the second solenoid so as to drive the hammer one more time.

Abstract: A speed controller operates a DC-powered fastener drive assembly to efficiently drive fasteners from a DC power supply, thereby achieving a fully portable hand tool. In particular, the speed controller accelerates a flywheel with a DC motor to a target speed appropriate for the type of fastener and user selection. Thereafter, the speed controller causes the kinetic energy from the flywheel to be imparted to a linearly moving fastener driver. The speed controller is responsive to the rotational speed of the flywheel to ensure a consistent depth of drive and to actuate a clutch for an appropriate amount of time to couple the flywheel to the fastener driver. Thereby, consistent drives are achievement across a range of operating conditions (e.g., battery state of charge, type of fastener, mechanical tolerances and wear, motor performance, etc.).

Abstract: Problems: To provide a stapler apparatus that can perform secure stapling operation and make the overall apparatus smaller in size and more stable in operation by suppressing deviation of driving position with a driver.

Abstract: Problems: To provide a stapler apparatus that can perform the secure transmission of driving force from a drive motor and cam members to a staple driving member and a staple bending member and make the apparatus body smaller and quieter in operation.

Abstract: A feeding mechanism for sheet staple comprises a reciprocating member (12) which is provided under a cartridge in which stacked sheet staples are contained and which is reciprocated forwardly and backwardly in response to up and down movements of a driver for driving the sheet staples, a feeding pawl (20) mounted rotatably by a predetermined angle in forward and backward directions on the reciprocating member (12) for rotating in a raised direction as the reciprocating member moves forwardly, and a spring (13) for biasing forwardly the reciprocating member (12).

Abstract: A nail stapler includes a magazine for containing nails and a gun for shooting the nails from the magazine. The gun includes a shell, a solenoid put in the shell, a mandrel put in the shell to be attracted from an original position to a punching position by means of the solenoid, a hammer secured to the mandrel and inserted through the solenoid, a spring for moving the mandrel to the original position from the punching position against the solenoid and a security device put in the shell for slowing down the mandrel when the mandrel is moved to the original position from the punching position by means of the spring.

Abstract: Stapling device (1) for stapling a workpiece (23), typically in the form of a sheaf of paper. The stapler (1) includes a support base (3) and a stapling unit (2) connected by a connecting piece (4) in a moveable manner. The stapling unit has a stapling magazine (6) in which staple blanks (24) are stored. A driver (7) is provided that drives the stapler so as to perform a stapling operation, and during which operation the workpiece is stapled. The support base is provided with an anvil (10) on which the workpiece is placed and against which stapling is carried out; the staple being secured in the workpiece with an orientation such that its longitudinal direction (T) is perpendicular to the longitudinal direction (L) of the stapler, whereby the connecting piece (4) extends along only one long side (21) of the stapler.

Abstract: This invention relates to the design of a pin clutch to allow for coupling of a rotational shaft to an output mechanism in a synchronous fashion. Specifically, this is related to impacting or operations requiring intermittent or semi-intermittent coupling of an input mechanism or shaft to an output mechanism or shaft. Devices of this nature include fastening tools, throwing mechanisms and other devices in which input energy is built up during a portion of a cycle followed by the coupling and release of that energy to an output mechanism.

Abstract: A portable electric nailing gun operating from a power source. The motor accelerates a flywheel which at the appropriate energy state is coupled through a mechanism to an anvil acting directly on the nail. The motor accelerates a flywheel that is then clutched to the output anvil causing the nail to be driven. The position of the output anvil is sensed and once the nail is driven, the motor is dynamically braked reducing the excess energy in the flywheel. This method uses a highly responsive motor and power source which enables the motor to come up to speed, drive the nail and return to a low energy condition in less than 2 seconds. The electrical control circuit and brake allow precise control and improve safety. The power source is preferably a rechargeable low impedance battery.

Abstract: A stapler apparatus includes a cartridge 10 storing staples 200 detachably supported, a staple driving unit 103 in the front direction of the cartridge mounting, an urging means 205 to urge the cartridge 10 to the staple punching side, and an interlocking means 96 mounted and linked to the cartridge 10 staple punching unit 103 to operate the urging means 205 onto the cartridge 10. The construction provides a stapler apparatus that allows the easy mounting of a cartridge and that can effectively urge a cartridge toward the punching station of the cartridge.

Abstract: Disclosed and taught herein is a novel vacuum return mechanism whereby the operating mechanism of a cyclic tool may be reset to its start position after having completed its operative cycle. A piston connected to the tool's operating mechanism is caused, by action of the tool's operating mechanism, to create a vacuum within a cylinder during the tool's operative cycle. Upon completion of the tool's operative cycle, the vacuum returns the piston, and thereby the tool's operating mechanism, back to their start positions.

Abstract: A stapler apparatus of the type using continuous belt-formed staples 200 includes a staple feed claw 25 for advancing the staples 200 sequentially to a stapling position 103, and a drive means 50 for driving the staples 200 drawn to the stapling position 103. A clincher means 40 bends the ends of the staples 200 driven into the sheets and pivots a staple feed pawl 25 interlocked to the staple bending operation of the clincher means 40 for sequentially feeding the staples 200 to the stapling position 103. This construction lightens the load on the drive means to staple sheet stacks, facilitates smooth driving operation of the drive means, and reduces the occurrences of trouble.