Abstract: A ratcheting driver for rotationally driving a piece and having a handle and pivotal pawls engageable with a driven gear and being capable of ratcheting and driving in both rotational directions. A cap is rotatable relative to said handle and it has a web for pivoting the pawls out of engagement with the gear. Through the selective rotation of the cap, the setting of the pawls is established. A spring positions the pawls in driving positions, and the cap has surfaces which disengage the pawls from the gear upon rotation of the cap. A method of arranging the driver is included.

Abstract: A ratchet wrench includes a wrench head, a handle pivotally connected to the wrench head, a retaining member having retaining and actuating ends and movable longitudinally relative to the handle to engaging and disengaging positions so as to engage and disengage the wrench head, an actuating member movable transversely relative to the handle to first and second positions so as to move the retaining member to the engaging and disengaging positions, and a biasing unit disposed to bias the actuating member toward the retaining member longitudinally so as to ensure immobility of the actuating member in the first position.

Abstract: A pass through socket (12) and wrench (10) combination is disclosed wherein a first drive member (22a, 22b) is provided on the socket's exterior surface and a second drive member (24) is provided on the front side of the ratchet wrench's wheel (26) for engaging the socket's first drive member (22a, 22b) to enable the socket (12) to be driven with the wrench (10). The wrench's wheel (26) defines an axially aligned through hole (30) extending through the wheel (26) for receiving an insertable end of the socket (12) through the front side of the wheel (26). Socket retention means, preferably a snap ring mounted on the front side of the ratchet wheel (26), is also provided.

Abstract: A ratchet wrench includes a body with a head portion and a shaft. The head portion includes a cavity. A rotatable member is received by the cavity and is rotatable about an axis. The rotatable member has a plurality of teeth disposed around a circumferential surface thereof. A reversing member is pivotally mounted to the body, and is movable between a first position and a second position. A pawl is connected to the reversing member such that the pawl moves circumferentially relative to the axis of the rotatable member as the reversing member moves between the first and second positions. The pawl includes a plurality of teeth that intermesh with the plurality of teeth on the rotatable member. Substantially all of the teeth of the pawl remain intermeshed with the teeth of the rotatable member as the reversing member moves between the first position and the second position.

Abstract: A screwdriver includes a handle, a first body having an end securely mounted in the handle, a second body rotatably mounted in the first body, a ratcheting mechanism slidably mounted in a receiving section in the other end of the first body, and a switch member pivotally mounted to the other end of the first body. The switch member is pivotable between a first position and a second position to control engagement/disengagement of the ratcheting mechanism with/from teeth of the second body and to control relative rotation between the first body and the second body. A reinforcing member is provided in the receiving section to withstand high-torque operation.

Abstract: A ratcheting tool includes a handle and a head with a compartment. A drive member includes a first end extended beyond the compartment, a second end extended beyond the compartment, and a gear wheel formed between the first end and the second end. The gear wheel is rotatably mounted in the compartment and includes a toothed outer periphery. A pawl is mounted in the compartment and includes a toothed side facing the gear wheel teeth. The toothed side of the pawl includes a first teeth portion having a first center of curvature and a second teeth portion having a second center of curvature located at a position different from the first center of curvature.

Abstract: A ratchet screwdriver and method of making same wherein there is a handle and there is a ratchet gear and pawls inside the handle. An adjuster is inside the handle and is movable by a tool extending into the handle for positioning the adjuster relative to the gear and thereby eliminating play between the gear and the handle. Ball bearings are interposed between the handle and the gear and the bearings rotatably support the gear and transmit the anti-play forces that act on the gear.

Abstract: A wrench includes a wrench body, an actuating member, a pawl member, a direction control knob, a positioning device, and a driving member. Thus, the direction control knob is mounted on the drive head of the wrench body after assembly of the pawl member and the driving member, so that the direction control knob is mounted on the drive head of the wrench body easily, rapidly and conveniently, thereby facilitating assembly of the wrench and thereby decreasing costs of production.

Abstract: A ratchet wrench rotatably operable in a vertical plane for removal and installation of a fastener includes a body with a shank portion and outwardly extending first and second member forming an offset in such body. A first ratchet mechanism disposed in a first head of the wrench attached to the first member and a second ratchet mechanism disposed in a second head attached to the second member are identical except for rotational direction enabling to remove the fastener with one end and install the fastener with the other end of the wrench.

Abstract: A ratchet wrench including a head section formed with two slots and two pawls each having a post slidably fitted through the slots. The ratchet wrench further includes a shift member formed with two slots respectively intersecting the slots of the head section. The posts of the pawls are slidably inlaid in the slots of the head section and the slots of the shift member. By means of shifting the shift member, the pawls can be directly driven to slide along the slots, whereby one of the pawls is engaged with the ratchet wheel, while the other of the pawls is disengaged from the ratchet wheel.

Abstract: A ratchet wrench includes a handle, a drive head, a ratchet wheel, a pawl member, a control knob, a positioning plate, and an urging spring. Thus, the ratchet wrench includes a positioning plate to push the pawl member, thereby reducing the volume of the ratchet wrench efficiently. In addition, the urging spring is supported and guided by the guide shaft of the positioning plate, so that the positioning plate is not easily deformed, thereby facilitating movement of the urging spring in the positioning plate.

Abstract: A flat headed, reversible power ratchet of relatively small size which uses integral bosses and apertures in its housing to locate and control the movement of its yoke and driving gears on bosses integral to the housing with the driving gear mounted in a bore within the yoke, which has its pawls and pawl controls within the yoke adjacent the gear, and by utilizing a pair of linkages which pivot about the yoke and about the housing in overlapping arcs to stabilize the position of the directional controls during operations.

Abstract: A oneway ratchet wrench includes a wrench body, a ratchet wheel, and a drive mechanism. The drive mechanism includes a support plate, a oneway pawl member, and an elastic member. Thus, the elastic member is mounted between the support plate and the oneway pawl member, so that the wall of the receiving recess of the drive head needs not to additionally provide a blind hole for mounting the elastic member, thereby facilitating assembly of the oneway ratchet wrench, and thereby decreasing costs of fabrication.

Abstract: The direction control device comprises a spanner body having a receiving chamber at a head portion thereof; a lateral side of the receiving chamber formed with a braking groove; the spanner body having a direction control groove communicated to the braking groove; a ratchet wheel being received in the receiving chamber and a brake block being received in the braking groove; the brake block being engaged to the ratchet wheel; a direction control unit received in the direction control groove; the direction control unit including a direction control block, a control sheet, and an elastic ejecting device; one end of the direction control block being formed with a control portion; and an upper end of the brake block capable of engaging with a ratchet wheel; a lower end of the brake block having an inserting hole and the brake block being formed with a notch near the inserting hole.

Abstract: A gear wrench allowing easy force application, having: a head, formed with a receiving compartment thereon for receiving a gear ring, the head extending along a first plane; a tail, extending along a second plane; and a neck, provided between and integrally formed with the head and the tail; characterized in that: the first plane is parallel to the second plane, and the neck obliquely extends from the head towards the tail to form a height difference between thee head and the tail. As such, the vertical component of force may be eliminated or minimized so as to effectively reduce occupational hazards; the horizontal component of force may also be increased such that the operator only requires a lower force to effectively tighten or loosen up a fastener.

Abstract: A ratchet socket tool includes a socket having a toothed protrusion extending axially from an end thereof and a tube is mounted on the first end of the socket. A driving member rotatably inserts into the tube and has a passage defined axially therethrough and a recess is defined in an inner periphery of the passage so that a pawl is movably engaged with the recess and has a toothed surface for being engaged with the toothed protrusion of the socket. A biasing member has a first end engaged with a notch defined in an inner periphery of the tube and a second end of the biasing member extends through a hole defined through a wall of the driving member and engaged with a concavity in the pawl so as to push the pawl to engage with the toothed protrusion.

Abstract: A driving member securing device for a hand tool includes a control member which has a skirt portion and a flange extends from an inner periphery of a central hole of the control member. The flange has a plurality of projections. The hand tool has a toothed wheel rotatably received in the head of the hand tool and an engaging hole is defined through the toothed wheel. The driving member has an insertion which is inserted into the engaging hole of the toothed wheel and includes a plurality of ridges and grooves. A groove is defined in the ridges and the grooves so that the flange of the control member is movably engaged with the groove to secure the driving member.

Abstract: A socket wrench for ratchet wheel sockets, comprises a handle having a recess at a first terminal thereof, an empty space between a pair of ear portions defining the recess, each of the ear portions being provided with an axial hole; a drive piece for retaining a ratchet wheel on which a ratchet wheel socket can be mounted, the recess of the handle being capable of receiving a pivotal portion of the drive piece; and a retaining pin for connecting the handle and the drive piece by being inserted though the axial holes of the ear portions and the pivotal portion of the drive piece. The drive piece can be folded about the retaining pin to change the angular position of the drive piece with respect to the handle.

Abstract: An opener comprises a holding portion; a front end of the holding portion being installed with a screwing portion; a rear end of the holding portion being installed with a rotation portion; a front end of the screwing portion being installed with an opener head; a rear end of the rotation portion being installed with a connecting hole for receiving a tool so as to provide a longer arm of force to have a larger torque, thus the user can moving a screwing element easily by using the opener. A section of the rotation portion is received into the holding portion; the section of the rotation portion is installed with at least one buckling ring for enhancing the engagement of the rotation portion with the holding portion. A front end of the portion of the rotation portion has a connecting sleeve; the screwing portion is tightly received into the connecting sleeve.

Abstract: A wrench includes a wrench body having a ring portion and a handle portion. A retainer that holds a plurality of wedge members is disposed inside the ring portion. Wedge guide grooves are formed on the inner circumferential surface of the ring portion. Each of the wedge guide grooves has a free region which maintains the corresponding wedge member in a free state, and left-hand and right-hand wedge regions each of which maintains the corresponding wedge member in a caught state. The wrench is provided with a changeover mechanism for moving the retainer to a position at which the wedge member faces the corresponding free region, a position at which the wedge member faces the corresponding left-hand wedge region, or a position at which the wedge member faces the corresponding right-hand wedge region.

Abstract: A wrench includes a body, a control device, a pawl and a joint. The body includes a handle and a ring. The control device includes a disc pivotally received in the ring and a stem projecting from the disc and including upper, lower and intermediate sections. The pawl is connected with the disc and formed with a toothed end for engagement with the teeth of the ring and two arc-shaped sides. The joint includes a disc received in the ring, an insert installed beneath the disc, stops installed on the disc for selective engagement with the arc-shaped sides of the pawl, and a ball detent trapped in a hole defined in the insert for selective engagement with one of the intermediate and lower sections of the stem.

Abstract: A ratchet wrench includes a wrench body having a drive head formed with a receiving recess, a ratchet wheel rotatably mounted in the receiving recess of the drive head, a positioning member secured in the receiving recess of the drive head and secured on the ratchet wheel to retain the ratchet wheel in the receiving recess of the drive head, and an oil seal secured in the receiving recess of the drive head and enclosed around the positioning member. Thus, the positioning member is a C-shaped snap that can abut and press the oil seal so as to position the oil seal actually, so that the oil seal has a better positioning effect.

Abstract: A wrench assembly includes a handle and a wrench. The handle includes a head. The wrench includes a first annular ring non-rotationally put in the head of the handle, a second gear rotationally installed in the first annular ring for engagement with a tool bit and a one-way driving device arranged between the first annular ring and the second gear so that the first annular ring can drive the second gear in a direction through the one-way driving device.

Abstract: The ratchet wrench of this invention includes a jaw adjustment assembly connected with a jaw and gear assembly carried by a wrench head. Components of the jaw adjustment assembly include a scroll plate inside a cap operated by a jaw adjustment disk located above the cap. The jaw adjuster disk is connected with the scroll plate using a snap ring. Components of the jaw and gear assembly include a pair of jaws supported and guided inside a gear unit with the aid of parallel support rails. The support rails connect the rear unit with the jaws and support the jaw and gear assembly from a wrench head and handle. The two assemblies are pressed and held together by a splined inner surface of the cap interfacing with a splined outer surface of the gear unit. A typical pawl assembly provides the ratchet operation of the ratchet wrench.

Abstract: A single-direction operation type ratchet wrench structure includes an elongated handle, and an identification portion. The handle has one end provided with a socket end, and a ratchet wheel is mounted in the socket end and operated in one direction only. The identification portion is mounted on the handle, and mates with a rotation direction of the ratchet wheel for locking or unlocking a workpiece, so that when a user holds the handle of the single-direction operation type ratchet wrench structure, he may directly identify the correct rotation direction for locking or unlocking the workpiece by the location and the direction of the identification portion on the handle, thereby facilitating the user operating the single-direction operation type ratchet wrench structure.

Abstract: A joint apparatus is provided for firmly connecting a head of a wrench with a socket. The joint apparatus includes a joint and a retainer. The joint includes a first portion for releasable engagement with the head of the wrench and a second portion for releasable engagement with a socket. The retainer is attached to the first portion of the joint for abutting the head of the wrench, thus avoiding the joint escaping the head of the wrench.

Abstract: A ratchet wrench is provided which includes a handle having a head on the handle, a rotatable gear disposed in the head and having ratchet teeth, and a pivotable pawl engaged with the gear to allow ratcheting rotation of the gear in a first direction and prevent ratcheting rotation of the gear in a second direction. An obstruction is engageable with a cam surface at the base of the pawl in order to prevent the pawl from self-reversing.

Abstract: A ratchet wrench with a releasable socket which is rotatable in a handle circular pocket and the socket extends on the wrench for only the thickness of the handle and does not protrude beyond the handle. The socket is symmetrical in its configuration and is therefore reversible in its position in the pocket and it still produces the same rotational drive. A pawl and spring are on the handle, and the pawl is snug with the socket to hold the socket in an axially fixed position on the handle. The pawl protrudes from the handle and indicates the rotational drive direction required of the handle. Fluid clean-out holes extend into the pocket.

Abstract: A socket adapter for a ratchet wrench, in which the bottom of the base body of the adapter comprises a coupling portion for engaging with a socket wrench or other liked tools. At the top surface of the base body a locking nut is rotatably disposed for inserting in a drive ratchet of the ratchet wrench. The locking nut is provided with a hexagonal portion at periphery thereof; by rotating the locking nut through a certain angle, the hexagonal portion is accordingly locked manually with any corner of the drive ratchet of the ratchet wrench, such that the socket adapter of the present invention can be detachably fixed in the drive ratchet of the ratchet wrench.

Abstract: A quick rotation wrench includes a driving portion, a wrench body, and an angle adjustment structure. The angle adjustment structure includes a control knob, two pawl members, two positioning members, and an elastic member. Thus, the included angle between the wrench body and the driving portion can be adjusted freely and arbitrarily. In addition, the included angle between the wrench body and the driving portion can be adjusted easily and conveniently. Further, the control knob is mounted on the wrench body, so that the user can use his one hand to press the control knob and operate the wrench body easily and conveniently, thereby facilitating the user operating the quick rotation wrench.

Abstract: A ratchet wrench includes a ratchet wheel received in the bore of a head and having a number of teeth, and having an engaging hole for receiving a socket adapter. A pawl may control the ratchet wheel to be driven by the head. The socket adapter includes a shell engaged in the ratchet wheel, and a shank extended from the shell for engaging with a tool member. Two balls are engaged in the shell and the shank. A shaft is slidably engaged in the shell and the shank for selectively actuating the balls to engage with the lower portion of the ratchet wheel and the tool member simultaneously.

Abstract: A unidirectional braking structure of a ratchet wrench comprises: a circoid surface with ratchet teeth disposed on the surrounding wall of an accommodating space at the working end of the wrench; a work piece wheel disposed in the accommodating space of said wheel; a plurality of restricting grooves, equidistantly disposed on the work piece wheel corresponding to the circoid surface with ratchet teeth; a plurality of direction restricting members disposed in the restricting grooves one by one, having a wheel teeth latching end to be engaged with the circoid surface with ratchet end; a plurality of springs disposed between the bottom of the restricting groove and the direction restricting member; such structure enables the present invention to enhance the torque of the wrench, reduce the loading of direction restricting member and the probability of damage, and have the merits of facilitating the manufacturing and assembling.

Abstract: A ratchet tool includes a head having a hole for receiving an engaging member therein and a recess is defined in an inner periphery of the hole so as to receive a pawl which is engaged with the engaging member. A passage is defined through the head and communicates with the recess. Two notches are defined in an inner periphery of the passage. A shifter member is rotatably received in the passage and has a lever is located on an outside of the head. A bead and a spring are received in a hole of the shifter member and the bead is engaged with one of the two notches. The spring is engaged with a second side of the pawl.

Abstract: A wrench structure includes a wrench handle, a drive body, two directional blocks, and a direction control member. The wrench handle has a drive head formed with a receiving chamber for mounting the drive body and a guide slot for mounting each of the two directional blocks. The drive head has an end face formed with a direction control recess and a spacing portion located between the receiving chamber and the direction control recess, for enhancing the structural strength of the wrench handle. The direction control recess is formed with a limit portion for limiting and guiding each of the two directional blocks, so that each of the two directional blocks may be moved to a determined position exactly, thereby changing the direction of operation of the wrench handle and the drive body actually.

Abstract: The present application relates to a ratchet wrench with improved force distribution between the pawl and the ratchet gear.

Abstract: A ratchet wrench is provided which includes a handle having a head on the handle, a rotatable gear disposed in the head and having ratchet teeth, and a pivotable pawl engaged with the gear to allow ratcheting rotation of the gear in a first direction and prevent ratcheting rotation of the gear in a second direction. An obstruction is engageable with a cam surface at the base of the pawl in order to prevent the pawl from self-reversing.

Abstract: A ratchet tool includes a head with a hole and a driving member is rotatably received in the hole. A plurality of teeth are defined in an inside of the hole and a plurality of notches are defined in an outer periphery of the driving member. Each notch has a pawl received therein which is engaged with the teeth. A spring ring is mounted to the pawls and positions and pushes the pawls in the notches.

Abstract: A reversible ratchet wrench which uses a pawl that can be moved between a right position and a left position. The pawl is in continuous connection with a rotatable ratchet wheel. The ratchet wheel rotates freely in a clockwise direction when the pawl is in the right position and is fixed to the wrench body when in the left position. The ratchet wheel rotates freely in a counterclockwise direction when the pawl is in the left position and is fixed to the wrench body when in the right position. A drive plate is mounted on the panel and is connected to a mechanism which is manually moved to cause the pawl to move.

Abstract: A wrench device has a bearing-type clutch for providing a unidirectional rotational force and an opposite unidirectional independent rotation. The device includes at least one bearing movably disposed in a tapering space between primary and secondary bodies. A displacement member engages and dislodges the at least one bearing from a binding location to a free location. A switch is pivotally disposed on the secondary body. A pivot member or gear is pivotally disposed between the switch and the displacement member such that pivoting the switch in one rotational direction results in movement of the displacement member in an opposite rotational direction.

Abstract: A ratcheting tool includes a handle and a head with a compartment. A drive member includes a first end, a second end, and a gear wheel formed between the first end and the second end. The gear wheel is rotatably mounted in the compartment and includes a toothed outer periphery. A pawl is mounted in the compartment and includes a toothed side facing the gear wheel teeth. A reversing plate is mounted to the first end of the drive member and pivotable about the rotational axis of the gear wheel between a first position and a second position. The reversing plate comprises a retainer block operably connected to a recess in an upper end of the pawl for moving the pawl between a first ratcheting position and a second ratcheting position.

Abstract: A head of a wrench comprises a hole having a center and a radius. The head further includes a compartment communicated with the hole. A wall defining the compartment has a center of curvature and a radius of curvature. A ratio between the radius of curvature of the wall and the radius of the hole is equal to or greater than 0.5, but less than 1. A distance between the center of the hole and the center of curvature of the wall is selected to form a deeper compartment to thereby improve the torque-bearing capacity.

Abstract: A pipe cutter includes a handle, a power-forcing handle, a position recovery member, a drive device, a revolving member, and a cutter device combined together. The handle and the power-forcing handle are pivotally combined together, and pressing the power-forcing handle toward the handle to force the drive device to revolve the revolving member and the cutter device to cut off a pipe placed in the revolving member. The pipe cutter is easy to handle by only pressing the power-forcing handle in cutting a pipe.

Abstract: A ratcheting tool includes a handle and a head with a compartment. A drive member includes a first end extended beyond the compartment, a second end extended beyond the compartment, and a gear wheel formed between the first end and the second end. The gear wheel is rotatably mounted in the compartment and includes a toothed outer periphery. A pawl is mounted in the compartment and includes a toothed side facing the gear wheel teeth. The toothed side of the pawl includes a first teeth portion having a first center of curvature and a second teeth portion having a second center of curvature located at a position different from the first center of curvature. A ring is mounted in the compartment and around the first end of the drive member. The ring is operably connected to the pawl such that the ring and the pawl are pivotable about a rotational axis of the gear wheel and that the pawl is movable in a radial direction relative to the ring.

Abstract: A head of a wrench comprises a hole having a center and a radius. The head further includes a compartment communicated with the hole. A wall defining the compartment has a center of curvature and a radius of curvature. A ratio between the radius of curvature of the wall and the radius of the hole is equal to or greater than 0.5, but less than 1. A distance between the center of the hole and the center of curvature of the wall is selected to form a deeper compartment to thereby improve the torque-bearing capacity.

Abstract: A wrench is described for turning various fasteners. The wrench has a predetermined entire length and comprises a driving portion at one end thereof for turning various fasteners. The driving portion has a predetermined length and an axis of wrench rotation. The wrench also has a gripping portion at the other end thereof for gripping and operating the wrench. The gripping portion has dimensions of length greater than width, and width greater than thickness and is formed elliptically shaped as viewed from a top view thereof, and is formed elongated in shape as viewed from an end view thereof. The gripping portion is further formed with a length relative to the entire length of the wrench and the length of the driving portion, whereas, the length of the gripping portion is about equal to, the entire length of the wrench less the length of the driving portion.

Abstract: A composite box end wrench has a non-metallic body including a handle portion and at least one head portion which defines a fastener-receiving opening therethrough. The wrench includes strengthening and/or retaining structure which strengthens the head portion and can change the failure mode to confine wrench parts in the event of failure. In one embodiment each head portion has a fastener-engaging member insert molded therein along with a reinforcing plate which encircles the member and preferably extends slightly into the handle portion. The reinforcing structure could alternatively be a band extending the length of the wrench and encircling the fastener-engaging member (or members in a double-ended wrench). In a ratcheting version of the wrench the non-metallic body may be split lengthwise into two parts, each of which has reinforcing structure embedded therein, the fastener-engaging member being a ratchet gear which, along with an associated pawl, is disposed between the body parts.

Abstract: A ratchet wrench comprises a wrench body having a handle portion and a pawl engaging surface. A ratchet gear is removably engaged with a fastener such that torque applied to the gear is transmitted to the fastener to effect rotation. The gear is mounted to the body such that the gear and the body are rotatable relative to one another about a gear axis. The gear has a plurality of gear teeth having opposing tooth surfaces. A pawl has first and second tooth engaging surfaces and a load receiving surface. The pawl is mounted to the body for pivotal movement about a pawl axis with the load receiving surface engaging the pawl engaging surface. The pawl is movable to a gear driving position wherein the first and second tooth engaging surfaces are positioned for driving engagement with respective tooth surfaces of a pair of the gear teeth.

Abstract: An elongated hollow handle forms a circular thru opening at one end. An annular ratchet gear is rotatably mounted within the handle and exposed in this opening and is adapted to carry a tool such as a die nut releasably secured within the gear and exposed thru opening. A double acting swivel pawl is centrally pivoted within the hollow handle and has two spaced pawl projections equally spaced from the pivot axis of the swivel pawl. A. transversely movable slider has opposite push buttons alternately protruding from the sides of the hollow handle; this slider has a spring bias plunger adapted to engage alternately opposite notches made in the rocker member on each side of its pivot axis. Therefore, a simple push on the protruding push button will change the direction in which the gear is rotated when swinging the handle back and forth. The gear has knurled exposed surfaces to enable manual grasping of the gear to brake its rotation during ratcheting.

Abstract: A socket adaptor is mounted to a box end of a ratchet-type ring spanner of the type having a hollow ratchet wheel rotatably mounted in the box end. The socket adaptor includes a disc, a mediate section projected from the disc and releasably engaged with the hollow ratchet wheel mounted in the box end of the wrench, and a distal socket engaging portion beyond the hollow ratchet wheel. The mediate section of the socket adaptor has an outer periphery for releasably engaging with an inner periphery of the hollow ratchet wheel to rotate therewith. The distal socket engaging portion is to be releasably engaged with a socket.

Abstract: A roller-type ratchet device is used for a wrench which includes a driving head defining a receiving hole and a plurality of actuating recesses. The ratchet device includes a driving body secured in the receiving hole to rotate with the driving head, a follower secured between the driving body and the driving head and having a plurality of fixed portions each mounted in a respective one of the actuating recesses, a plurality of locking members each secured in a respective one of the fixed portions of the follower to move therewith, and each pressing the driving body, and a direction control knob pivotally mounted on the driving head and engaged with the follower for moving each of the locking members in the respective actuating recess between different positions.