FIELD OF INVENTION

The present invention generally relates to adjustable ratchet wrench or spanner and more particularly to an improvement to a ratchet wrench or spanner, with an adjustable lower jaw element and a moveable upper jaw element.

BACKGROUND OF INVENTION

This application is a continuation of U.S Pat. No. 7, 201, 084 B2 by Wang Han Yap entitled "ADJUSTABLE RATCHET WRENCH" granted on April 10, 2007.

A prior art wrench or spanner is a tool used to provide a mechanical advantage in applying torque to turn bolts, nuts or other hand-to-turn items. Particularly, it is a tool for gripping and turning hexagonal nuts on screws bolts and so on. A common wrench or spanner, for example, a folk spanner comprises essentially a handle portion integrally cast with one U-shaped gripping portion at each end, where two extending elements of the U-shaped gripping portion are parallel to each other permanently. Said folk spanner also known as open-ended spanner and it is usually double-ended with different sized opening at each end. For another example, a ring spanner or box-end wrench comprises essentially a handle portion integrally cast with one ring gripping portion at each end. Said ring gripping portion of the ring spanner typically is an enclosed opening that grips the faces of the bolt or nut. The enclosed opening usually includes a recess of six-point or twelve- point opening for use with nuts or bolt heads of hexagonal shape. Eight-point opening may also provide for square-shaped nuts and bolts head. The ring spanner is often double-ended and usually with offset handles to improve access to the nut or bolt.

Still another example is a socket wrench which makes it easy to use is a oneway ratchet connection between a wrench handle and a socket-receiving stub, so that once a wrench socket is engaged with nut or bolt head, the wrench handle can be turned clockwise to tighten the nut or bolt head and turned counterclockwise to start a new stroke without having to disconnect the socket from nut or bolt head. Socket wrench however has disadvantage that a different socket is required for each size nut or bolt head.

Yet, another example is an adjustable spanner which comprises essentially a handle portion with an adjustable gripping portion, where an upper jaw element of the gripping portion is generally immovable and a lower jaw element is ratchet adjustable. In use, for example, the gripping portion is adjusted to fit a width across flats of a hexagonal nut or bolt head. After a tightening or loosening action, the adjustable wrench or spanner will be displaced from its initial position. To continue with the action, the wrench or spanner needs to be removed from the nut or bolt head first, and then engages a new width across flats of the nut or bolt head. Accordingly, the wrench or spanner must be disengaged from the nut or bolt head and re-engaged on each stroke. This latter engaging movement may be cumbersome and difficult to achieve, depending on certain circumstances. For example, this is particularly time consuming when location of the nut or bolt head to be tightened is nearby obstructions limit length of the wrench stroke, thus necessitate frequent disconnection and reconnection of the wrench with nut or bolt head.

Throughout the years, a number of innovations have been developed relating to adjustable ratchet wrench, and the following U.S. patents are representative of some of those innovations: U.S. Pat. No. 4, 913, 011, U. S. Pat. No. 5, 095, 782, and U.S. Pat. No. 5, 957, 008.

U.S. Pat. No. 4, 913, 011 discloses a snap-fit self-adjusting ratchet wrench includes two guild jaws which move linearly against each other along a guided pin, and which are hinge to handle by pins. The hinges on the jaws to the handle are designed with override leverage wherein the gripping force is increased as the handle is swung in forward stroke and releases in back stroke to provide ratchet action. A return spring exerts force on the jaws for an automatic snapping on the workpiece and a locking mechanism is provided for retaining the guiding pin to hold the jaw opening to a fixed predetermined position.

U.S. Pat. No. 5, 095, 782 discloses an open-ended adjustable ratchet wrench having a fist jaw with a fastener contact surface thereon is slideably connected to a second jaw with a second fastener contact surface thereon for grasping a nut or bolt. A link member is provided to pivotally attach with the first jaw along a first axis and an elongated handle is pivotally attached at one end thereof to the link member along a second axis. A rack having plurality of teeth thereon is disposed on the second jaw for movement with said second jaw and is in engagement with a pinion gear rotatably attached to the link member about the first axis. A pawl is pivotally attached to the link member and has a first pivotal position for selectively engaging the teeth of the pinion gear for preventing rotation of the pinion gear in one rotary direction. The pawl permitting rotation of the pinion gear in the opposite direction and has a second pivotal position wherein the pinion gear can rotate in the opposite direction and be prevented from rotating in the first said rotary direction. A set of teeth is disposed on one end of the elongated handle for rotating with the handle about the second axis and a second set of teeth is disposed on the first jaw. The second set of teeth is engageable with the first set of teeth for causing the first jaw to pivot about the first axis in response to pivoting of the first set of teeth and the elongated handle about the second axis. U.S. Pat. No. 5, 957, 008 discloses a new adjustable wrench construction wherein the same can be utilized for including forward, reverse and neutral operative positions. The inventive device comprises in combination, a ratchet head assembly, an upper handle portion, an intermediate connector portion, a lower handle portion and a push button disposed within a cylindrical housing. The ratchet assembly allows a gripping portion to be placed over a hexagonal nut. The tightening or loosening action of the nut can be continually carried, without having to shift from the widths across flats.

Each of these references teaches an adjustable ratchet wrench for engaging variety of bolts or nuts, with the ratcheting mechanism being based on camming operations in which one or both jaws rotate with respect to the wrench handle. For the most part, these devices are relatively complex and expensive to manufacture, and some of them may subject to excessive mechanical wear over a certain time period. Some above mentioned adjustable ratchet wrench may also not suitable for use in tightening or loosening the square-shaped or other than hexagonally-shaped nuts or bolt heads. For those adjustable ratchet wrenches which essentially require spring means, it may tends to breakdown over certain time period and become malfunction. The inventor believe that there is a need in the art still exists for an improved adjustable ratchet wrench or spanner which incorporates simple features and design while maintaining a reasonable cost for it. Moreover, there is a need for an adjustable ratchet wrench or spanner which provides fast and easy tightening or loosening action, without having disengagement from workpiece.

SUMMARY OF INVENTION

A main object of the present invention provides an improved adjustable ratchet wrench or spanner which can be used for continual tightening or loosening action on a workpiece of different sizes and specifications, without having disengagement from the workpiece.

Another object of the present invention is to teach an improved adjustable ratchet wrench or spanner, with an adjustable lower jaw element and a movable upper jaw element. Yet, another object of the present invention provides an improved adjustable ratchet wrench or spanner to facilitate user operating a single adjustable ratchet wrench or spanner to operate workpiece of different sizes and specifications, thereby enhancing versatility of the improved adjustable ratchet wrench or spanner.

Still yet another object of the present invention provides an improved adjustable ratchet wrench or spanner which is durable and reliable construction.

Still another object of the present invention provides an improved adjustable ratchet wrench or spanner which may easily and efficiently manufactured and marketed.

To achieve at least one of the above objects, the present invention teaches an improved adjustable ratchet wrench or spanner which comprises a ratchet assembly; an elongated handle element with a primary urging portion at one end pivotally connected to the ratchet assembly; an upper jaw element with an upper urging portion pivotally connected to the ratchet assembly; a lower jaw element with a rack member in cooperating with cylindrical worm screw adjustably connected to the ratchet assembly; characterized in that the adjustable ratchet wrench or spanner further includes:- a) a lower urging portion having a first projecting portion and a second projecting portion integrally joined at the protruding knob forming a substantially L-shaped member; b) a receiving socket disposed at the upper urging portion to receive a protruding knob of the lower urging portion; c) a substantially V-shaped groove provided at the primary urging portion, defining an upper convex tip and a lower converging tip, disposed at predetermined position in communication with the lower urging portion; wherein the protruding knob is matingly engaged or interlocked with the receiving socket so as to enable rotational movement of the upper urging portion and lower urging portion about an axis of protruding knob. The upper jaw element is moveable with assistance of the primary urging portion, lower urging portion and the upper urging portion. Upper and lower jaw portions are operable in tightening or loosening positions, negotiating different widths across flats of a workpiece without having disengagement from the workpiece.

Bottom surface of the lower urging portion is of substantially concave curve, allowing smoothable contact motion between pushing head of the spring means and the lower urging portion. The upper urging portion may be further provided with a protruded portion that acts as a stopping point for first projecting portion when the first projecting portion rotates upwardly about the axis of the protruding knob caused by loosening action.

The ratchet assembly comprises a housing body having a substantially elongated U-channel portion and a substantially opposite slot integrally meet in an inclined orientation. The substantially elongated U-channel portion is provided with first pin position, second pin position and a hollow passage to receive upper urging portions of the upper jaw element and primary urging portion of the elongated handle element.

The primary urging portion and the upper urging portions carries a first pin position and second pin position respectively aligning with the first pin portion and the second pin portion of the substantially elongated U-channel portion through a pin. The substantially opposite slot includes a hollow passage for slidable movement of the lower jaw element. The hollow passage further includes retaining portions. Said retaining portions are of matingly engageable with projecting fin and prevent rack member of the lower jaw element from being dislocated. Two lateral sides of the substantially opposite slot are optionally provided with a rectangular opening to accommodate cylindrical worm screw.

The lower jaw element moves slidably up or down parallely along shaft by turning the cylindrical worm screw.

A spring means is accommodated in an inclined portion of the U-channel portion at predefined compartment. Said spring means induces a compressive force against the second projecting portion of the lower urging portion thereby naturally urging the lower urging portion into locking position. The locking position is where the spring means induces compressive force against the second projecting portion upwardly; the first projecting portion in turn rotates downwardly about the axis of the protruding knob until reaching locking point on the inclined portion of the U-channel portion.

An upper gripping edge and a lower gripping edge of the upper and lower jaw portions are naturally in parallel at the locking position. Space between the gripping edges of the upper and lower jaw portions is adjustable to fit the width across flats of the workpiece of different sizes and specifications.

BRIEF DESCRIPTION OF DRAWINGS

In order for the present invention to be more readily understood, the following description is given by way of example, of one specific embodiment of an improved adjustable ratchet wrench or spanner made in accordance with the present invention. Reference will be made to accompanying drawings. The drawings constitute part of this specification and include an exemplary or preferred embodiment of the invention, which may be embodied in various forms. It should be understood, however, the disclosed preferred embodiment is merely exemplary of the invention. Therefore, the figures (not to scale) disclosed herein are not to be interpreted as limiting, but merely as the basis for the claims and for teaching one skilled in the art of the invention. In the appended drawings:

FIG. 1 is an exploded perspective view of various components making up an improved adjustable ratchet wrench or spanner in accordance with a preferred embodiment of present invention. FIG. Ia is an enlarged assembled side view of the improved adjustable ratchet wrench or spanner in a tightening position illustrating bottom surface of lower urging portion is of substantially concave curve.

FIG. Ib is a further enlarged view of FIG. Ia illustrating upper urging portion of upper jaw element is provided with an optionally protruded portion. FIG. Ic is an enlarged explodes bottom view of the improved adjustable ratchet wrench or spanner illustrating sectional configuration of lower jaw element and hollow passage.

FIG. 2 is an assembled side view of the improved adjustable ratchet wrench or spanner in a tightening position engaging a width across flats of a workpiece, partially exposing the relative positions of urging portions actuating on upper jaw portion.

FIGS. 3 and 4 are assembled side views of the improved adjustable ratchet wrench or spanner illustrating the movement of handle element in relation with urging portions, resulting the adjustable ratchet wrench or spanner in a loosening position negotiating the workpiece to a new width across flats, partially exposing the relative positions of urging portions actuating on upper jaw portion.

FIG. 5 is an assembled side view of the improved adjustable ratchet wrench or spanner illustrating the handle element is moving back to its tightening position engaging the new width across flats of the workpiece, partially exposing the relative positions of urging portions actuating on upper j aw portion.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

A detailed description of preferred embodiment of the invention is disclosed herein. It should be understood, however, that the embodiment is merely exemplary of the invention, which may be embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limiting, but merely as the basis for the claims and for teaching one skilled in the art of the invention. For ease of explanation, the present invention will be described hereafter where an improved adjustable ratchet wrench or spanner is placed in an upward orientation with a primary urging portion (11) disposed at one distal end of an elongated handle element (1). Similar features on different preferred components of present invention are differentiated with suffice such as "a" and "b". A workpiece, for example, a hexagonal nut or bolt has three pairs of widths across flats. In the subsequent explanation, two different widths across flats of the hexagonal nut are defined as "fl" and "f2". As looked at plan view of the hexagonal nut or bolt, a tightening action of the hexagonal nut implies a clockwise movement about its central axis, whereas a loosing or removing action implies an anti-clockwise movement.

Referring to FIG. 1, there is shown various components making up an improved adjustable ratchet wrench or spanner in accordance with a preferred embodiment of present invention. The improved adjustable ratchet wrench or spanner generally comprises an elongated handle element (1) with a primary urging portion (11) at one end, an upper jaw element (2) with an upper urging portion (21), a lower urging portion (26), a lower jaw element (4) with a rack member (44) in cooperating with a cylindrical worm screw (45) and a ratchet assembly (3). Preferably, said adjustable ratchet wrench or spanner can be made of, but not limited to metallic material. For example, a stainless steel or any other high strength metal, alloyed with vanadium to increase springiness, or alloyed with chromium to increase hardness and wear resistance of the wrench or spanner.

The primary urging portion (11) is of a substantially reduced dimension than that of a handle portion (14). The primary urging portion (11) and the handle portion

(14) are integrally connected making up the elongated handle element (1). The primary urging portion (11) is provided with a V-shaped groove (15), defining an upper convex tip (13) and a lower converging tip (16), disposed at predetermined position that in communication with the lower urging portion (26). Said primary urging portion (11) carries a first pin position (12a), which is to be aligned with another first pin portion (12b) on the ratchet assembly (3). Preferably, a pin (5) is introduced through a first pin position (12) for the alignment, and to provide pivotally joint between the elongated handle element (1) and the ratchet assembly (3). It will be appreciated that the handle portion (14) and the primary urging portion (11) are rotate about the first pin position (12) which acts as a fulcrum. It is important to note that the longitudinal axis of the elongated handle element (1) passes through the centre of the first pin position (12) of the primary urging portion (11).

The upper jaw element (2) includes an upper jaw portion (22) integrally adapted with the upper urging portion (21). Said upper urging portion (21) is provided with a receiving socket (28) to receive a protruding knob (29) of the lower urging portion (26). The receiving socket (28) is of substantially circular with a quadrant opening, and defining a knuckle joint to interlock with protruding knob (29) of the lower urging portion (26). Interlocking at the knuckle joint of the receiving socket (28) prevents dislocation of protruding knob (29) from the upper urging portion (21). The upper urging portion (21) may be further provided with a protruded portion (21a) that acts as a stopping point for first projecting portion (26a) when the first projecting portion (26a) rotates upwardly about the axis of the protruding knob (29) caused by loosening action (FIG. Ia and Ib).

The lower urging portion (26) generally formed of one-piece unitary member. Accordingly, the lower urging portion (26) comprises a first projecting portion (26a) and a second projecting portion (26b) integrally joined at the protruding knob (29) to form a substantially L-shaped member. Bottom surface of second projecting portion (26b) is preferably of substantially concave curve (26c) to allow smoothable contact motion between pushing head (34b) of spring means (34) and the lower urging portion (26) (FIG. Ia and Ib). It will be appreciated that the protruding knob (29) is matingly engaged with the receiving socket (28) to provide a free rotational movement to the lower urging portion (26). In particular, interlocking between receiving socket (28) and protruding knob (29) enable rotational movement of upper urging portion (21) and lower urging portion (26) about the axis of protruding knob (29). The upper jaw portion (22) of upper jaw element (2) carries an upper gripping edge (23) which operates in combination with a lower gripping edge (42) of a lower jaw portion (41). The space in between the upper gripping edge (23) and the lower gripping edge (42) constitute a mouth of a gripping portion for a workpiece. The workpiece may be of, but not limited to a hexagonal nut or bolt. It will be appreciated that the gripping portion enables the adjustable ratchet wrench or spanner of the present invention to operate on workpiece of different sizes and specifications. The upper urging portion (21) further includes a second pin position (24a) which is to be aligned with another second pin position (24b) on the ratchet assembly (3). Similarly, pin (5) is introduced through a second pin position (24) for the alignment, and to provide pivotally joint between the upper jaw element (2) and the ratchet assembly (3). Accordingly, the upper jaw portion (22) and the upper urging portion (21) rotate about the second pin position (24) which also acts as a fulcrum.

In tightening positon, the interlocking between receiving socket (28) and protruding knob (29) of the upper and lower urging portions (21, 26) defining an upper converging edge (25) and a lower converging edge (30) meeting at a converging point (27). It will be appreciated that a spring means (34) is provided underneath the second projecting portion (26b) of the lower urging portion (26). It is important to note that length of the upper urging portion (21) is substantially longer than the length of the primary urging portion (11).

An example of the ratchet assembly (3) will be described herein. The ratchet assembly (3) comprises a housing body (31) having a substantially elongated U- channel portion (32) and a substantially opposite slot (33) integrally meet in an inclined orientation. The elongated U-channel portion (32) is provided with first pin position (12b) and second pin position (24b). The upper urging portions (21) of the upper jaw element (2) and the primary urging portion (11) of the elongated handle element (1) are received inside a hollow passage defined in the elongated U-channel portion (32). Two pins (5) are inserted through the first and second pin positions (12, 24). The primary urging portion (11) and upper urging portions (21) engage each other between the two pin positions (12, 24), acting as fulcrum. The substantially opposite slot (33) of the housing body (31) having a hollow passage for slidable movement of the lower jaw element (4). The hollow passage further includes retaining portions (33a), said retaining portions (33a) being matingly engageable with projecting fin (43) and rack member (44) of the lower jaw element (4). Accordingly, the hollow passage and the retaining portions (33a) are of identical cross-sectional configurations to match the slot-in projecting fin (43) and rack member (44) of the lower jaw element (4) so as to prevent the lower jaw element (4) from being dislocated (FIG. Ic). Two lateral sides of the substantially opposite slot (33) of housing body (31) are optionally provided with a rectangular opening (35) to accommodate cylindrical worm screw (45).

The lower jaw element (4) includes the lower jaw portion (41) which is integrally attached with the rack member (44) by a projecting fin (43) extending therebetween. Located on the side of the rack member (44) opposite the projecting fin (43) is a plurality of spaced-apart notches forming a series of rack teethes (44a). The lower jaw element (4) with the rack member (44) in cooperation with the cylindrical worm screw (45) is adjustably connected to the ratchet assembly (3). Particularly, the rack teethes (44a) of the rack member (44) are in communication with a spiral worm tooth (45a) of the cylindrical worm screw (45) disposed within the substantially opposite slot (33) of housing body (31). The cylindrical worm screw (45) is securely configured at the rectangular opening (35) through a shaft (46). It will be appreciated that the cylindrical worm screw (45) is an exposed part on the housing body (31). By turning the cylindrical worm screw (45), the lower jaw element (4) moves slidably up or down parallely along the shaft (46). The space between the gripping edges (23, 42) of the upper and lower jaw portions (22, 41) thus can be adjusted to fit a width across flats of the workpiece, for example, hexagonal nut or bolt of different sizes.

It is important to note that the gripping edges (23, 42) of the upper and lower jaw portions (22, 41) are preferably parallel to each other, in tightening position. In tightening position, the elongated handle element (1) is given a clockwise torque about the first pin position (12), as illustrated in FIG. 2. The lower converging tip (16) of the primary urging portion (11) urges the second projecting portion (26b) of the lower urging portion (26) upwardly. This action, in turn, converts into anticlockwise torque about the second pin position (24) through the axis of the protruding knob (29). The upper gripping edge (23) of the upper jaw portion (22) moves downwardly to assume the parallel orientation with the lower gripping edge (42) of the lower jaw portion (41). To assist in the urging action, the spring means (34) is disposed between the base of the elongated U-channel portion (32) and the lower urging portion (26). There can be several examples of this spring means (34). By way of example and not by way of limitation, a compression spring (34a) with a pushing head (34b) is preferably fitted and accommodated in inclined portion of the U-channel portion (32) at predefined compartment (36). Said spring means (34) would naturally induces compressive force against the second projecting portion (26b) of the lower urging portion (26) upwardly. This may be considered as a default orientation of the lower urging portion (26) in locking position. Accordingly, the locking position is achieved when said spring means (34) induces compressive force against the second projecting portion (26b) upwardly; in turn, it rotates the first projecting portion (26a) downwardly about the axis of the protruding knob (29) until the first projecting portion (26a) reached at the locking point on the inclined portion of the U-channel portion (32). At this default orientation or locking position, the upper and lower gripping edges (23, 42) of the upper and lower jaw portions (22, 41) are naturally parallel.

In loosening position as seen in FIGS. 3 and 4, the elongated handle element (1) is given an anti-clockwise torque about the first pin portion (12). The upper convex tip (13) of the primary urging portion (11) urges the lower converging edge (30) of the second projecting portion (26b) downwardly. This action, in turn, converts into clockwise torque about the second pin position (24) through the axis of the protruding knob (29). The upper gripping edge (23) of the upper jaw portion (22) moves upwardly. This action caused the mouth of the gripping portion to be opened, which allows the upper and lower gripping edges (23, 42) of the upper and lower jaw portions (22, 41) to shift from one width across flats (fl) to another adjacent width across flats (f2) as shown in FIG. 5, without having the adjustable ratchet wrench or spanner of this invention disengaged from the hexagonal nut or bolt, due to the counter force from the spring means (34) applied on the lower urging portion (26). As soon as the upper gripping edge (23) of the upper jaw portion (22) passed the higher point of the hexagonal nut or bolt, the lower urging portion (26) will be returned back to the locking position by the compressive force acting on the second projecting portion (26b) of the lower urging portion (26) and the lower converging tip (16) acting on the second projecting portion (26b).

While embodiment of the invention has been illustrated and described, it is not intended that this embodiment illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation and various changes may be made without departing from the scope of the invention.