Wrench

The present invention provides a wrench, and its structure includes a guide rod, a first pawl mounted on the guide rod, a sliding member sheathed on the guide rod, a second pawl mounted on the sliding member and matching with the first pawl, and a toothed block disposed on the sliding member and matching with the guide rod. The toothed block has a first position and a second position. When the toothed block is in the first position, the toothed block is slidable along the guide rod toward the first pawl, and is locked in the direction away from the first pawl. When the toothed block is in the second position, the toothed block is slidable along the guide rod toward or away from the first pawl.

CROSS-REFERENCE TO RELATED APPLICATION

This application is the United States national phase of International Application No. PCT/CN2014/082038 filed Jul. 11, 2014, the disclosure of which is hereby incorporated in its entirety by reference.

FIELD OF THE INVENTION

The invention relates to a hand tool, and, in particular, relates to a wrench used for clamping a flat plate, a nut, and especially pipe fittings such as a steel pipe, a plastic pipe, etc.

DESCRIPTION OF THE PRIOR ART

In daily lives or works, a wrench is frequently used for clamping an object, such as for clamping pipe fittings such as a steel pipe, a plastic pipe etc., to implement loosening and tightening of mounting or dismounting. A traditional wrench, such as a pipe wrench, for clamping pipe fittings is generally composed of a fixed jaw, a movable jaw, a handle, an adjusting nut, etc. The fixed jaw is fixed together with the handle in a sophisticated structure. The traditional pipe wrench accomplishes opening and closing relying on the transmission by the thread pair between the nut and the movable jaw. In use, the adjusting nut is rotated constantly to enable the change in the opening size of the movable jaw relative to the fixed jaw by adjusting the sliding movement of the movable jaw, and, therefore, the operation is very inconvenient. Meanwhile, the opening and closing speed of the jaws of a traditional pipe wrench is limited by the pitch of the thread pair, unable to realize fast opening and closing of the jaws.

SUMMARY OF THE INVENTION

In view of the above defects in the prior art, the technical problem to be solved by the invention is to provide a wrench which has simple structure, flexibility of opening and closing, fast adjusting speed, convenience and reliability in using. The wrench can be used for clamping and rotating a pipe fitting, and also for clamping objects in other shapes such as a flat plate, a nut, etc.

In order to achieve the above object, the invention provides a wrench, the structure of which comprising: a guide rod, a first pawl mounted on the guide rod, a sliding member sheathed on the guide rod, and a second pawl mounted on the sliding member and matching with the first pawl, characterized in that, the wrench further comprises a toothed block disposed on the sliding member and matching with the guide rod, the toothed block having a first position and a second position; the wrench is configured such that: when the toothed block is in the first position, the toothed block is locked; when the toothed block is in the second position, the toothed block is unlocked.

Further, the first position refers to a position where the toothed block is located when the toothed block is engaged with the guide rod; the second position refers to a position where the toothed block is located when the toothed block and the guide rod are detached.

Further, when the toothed block is in the first position, the toothed block is slidable along the guide rod toward the first pawl, and is locked in the direction away from the first pawl; when the toothed block is in the second position, the toothed block is slidable along the guide rod toward or away from the first pawl.

Further, an engagement portion where the guide rod is engaged with the toothed block is provided with unidirectional teeth having a unidirectional orienting effect: when the sliding member is pushed toward the first pawl, the toothed block is slidable along toothed surface of the unidirectional teeth, so that the sliding member moves along the guide rod and comes close to the first pawl; when the sliding member is pushed away from the first pawl, a sliding movement of the toothed block along toothed surface of the unidirectional teeth is obstructed, so that a sliding movement of the sliding member along the guide rod is locked.

Further, the sliding member is provided with a sloping surface matching with the toothed block, a first angle provided between the sloping surface and the guide rod; the first angle enabling the toothed block to be subject to an acting force perpendicular to the guide rod and pointing toward the guide rod when the wrench is clamping a workpiece, the acting force facilitating the engagement of the toothed block and the guide rod.

Further, the first angle is arranged to be less than 90°.

Further, an engagement portion where the guide rod is engaged with the toothed block is provided with unidirectional teeth having a toothed surface, the toothed surface obstructs the sliding movement of the toothed block away from the first pawl, a second angle provided between the toothed surface and the sloping surface, the second angle enabling the unidirectional teeth to still be able to lock the toothed block when the unidirectional teeth deform.

Further, the second angle is arranged to be more than 0°.

Further, a reserved space is arranged between the toothed block and the sliding member, the reserved space enabling the toothed block to rotate by an angle allowing the toothed block to conquer the locking of the toothed block with respect to the guide rod produced due to the second angle, so that the toothed block is detached from the guide rod; meanwhile, the reserved space enables a plurality of teeth on the toothed block to automatically locate position to be engaged with the guide rod.

Further, the wrench also includes a connecting rod provided at both sides of the guide rod and connected to the toothed block.

Further, the wrench also includes a pushbutton connected to the toothed block by the connecting rod, when a pressing force is applied to the pushbutton, the connecting rod being able to transfer the pressing force to the toothed block, so that the toothed block is detached from the guide rod; when the pressing force applied to the pushbutton is canceled, the toothed block is reset to be engaged with the guide rod.

Further, a third angle is provided between the connecting rod and the sloping surface, and meanwhile, a fourth angle is provided between the connecting rod and the guide rod, the third angle and the fourth angle enabling the pressing force to which the pushbutton is subject to conquer the friction force between the toothed block and the sloping surface, so that the toothed block is detached from the guide rod.

Further, the third angle and the fourth angle are both less than 90°. Further, the wrench also includes a pushbutton and a connecting rod, the pushbutton, the connecting rod and the toothed block formed into a connecting member provided to be sheathed on the guide rod.

Further, the sliding member is provided with a first portion extending along the guide rod toward the first pawl, and the second pawl is embedded in the first portion.

Further, the sliding member is also provided with a second portion provided to be sheathed on the guide rod, the second portion being provided with a cavity arranged therein, the connecting member being arranged in the cavity.

Further, a portion of the pushbutton is embedded in the cavity, and another portion of the pushbutton protrudes out of the sliding member.

Further, the second pawl is provided with a hang tab embedded in the second portion and fixedly connected to the second portion by a pin rod.

Further, the wrench also includes a clamping surface provided on the first pawl and the second pawl.

Further, the first pawl is connected to the guide rod by a fixing pin arranged with a snap slot used for mounting a snap ring.

Further, a first spring is provided between the first pawl and the guide rod, and when a workpiece is clamped, the first spring can push the first pawl to move, so as to produce pre-tightening force in the workpiece.

Further, the wrench also includes a second spring being able to apply pressing force to the toothed block.

Further, one end of the second spring contacts the toothed block, and the other end contacts a coverplate fixedly connected to the sliding member.

Further, the outside of the sliding member is provided with a first concave part, and the coverplate is embedded in the first concave part, the coverplate fixedly connected to the sliding member by a screw.

Further, the screw is a flat screw, and a gap exists between the screw and the toothed block.

Further, the sliding member is also provided with a thumb abutting part facilitating an operator to push the sliding member to move, a surface of the thumb abutting part is provided with a second stripes, slots parallel to each other being between the second strips, for increasing the friction between the fingers of the operator and the thumb abutting part.

Further, the first spring is a spiral spring.

Further, the pushbutton surface is provided with a first stripes, slots parallel to each other being between the first strips, for increasing the friction between the fingers of the operator and the pushbutton.

Further, the clamping surface is provided with teeth used for increasing the friction between the clamping surface and the clamped workpiece.

Further, the second spring is a compressed spring.

Further, both sides of the guide rod are provided with a recess extending across the whole guide rod, such that, the connecting rod at either side of the guide rod is not in complete contact with the side of the guide rod, facilitating the toothed blocking to slide along the guide rod.

Further, the guide rod is provided with a grasp part which is a protection sleeve surrounding about the guide rod.

Further, the protection sleeve is fixedly connected to the guide rod by a fastener.

Further, the fastener is composed of a nut and a bolt.

Further, the protection sleeve is provided with a second concave part, and the nut is embedded in the second concave part.

Further, the protection sleeve is also provided with a hang hole, used for hangingly position the wrench.

The invention has the following advantages:(1) By fast sliding movement between the guide rod and the toothed block, the fast adjustment of the jaws, i.e. the distance between the first pawl and the second pawl, can be achieved.(2) The unidirectional teeth at the engagement portion where the guide rod is engaged with the toothed block have a unidirectional orienting effect. The second pawl is only allowed to move toward but not away from the first pawl when the sliding member is pushed, thus, the second pawl will not automatically move away from the first pawl so that the clamped object is dropped when clamping a workpiece, so that the clamped object is tightly clamped.(3) By applying a pressing force to the pushbutton, the toothed block can be detached from the guide rod readily, which is good for fast adjustment of the jaws. In addition, when canceling the pressing force to the pushbutton, the elastic force of the second spring can quickly reset the toothed block to be engaged with the guide rod.(4) The angle between the sloping surface of the sliding member and the direction along the length of the guide rod is arranged to be less than 90°, being able to increase the pressing force between teeth on the toothed block and the teeth on the guide rod, so that the toothed block is better engaged with the guide rod when the wrench is clamping a workpiece.(5) The angle between the connecting rod and the direction along the length of the guide rod is less than 90°, and the angle between the connecting rod and the sloping surface of the sliding member is less than 90°, so that once an act is applied to the pushbutton the toothed block can readily conquer the friction to slide down along the sloping surface of the sliding member when the wrench is not clamping a workpiece, so that fast detachment of the toothed block from the guide rod and, therefore, unlocking, can be achieved.(6) The unidirectional teeth on the toothed block and the guide rod have a toothed surface obstructing the sliding movement of the toothed block toward the first pawl. The angle between the toothed surface and the sloping surface of the sliding member is arranged to be more than 0°, such that the toothed block can still be locked and not detached from the guide rod when the wrench is clamping a workpiece even if deformation occurs to the unidirectional teeth.

Referencing now to the figures, the conception, detailed structure and induced technical effect of the present invention will be expounded for due understanding of the purpose, characterizations and effects of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now the invention is further described in combination with the accompanying figures and embodiments.

FIG. 1andFIG. 2are perspective views of the wrench100in a preferred embodiment of the invention, the structure thereof includes: a guide rod2, a first pawl1mounted on the guide rod2, a sliding member31sheathed on the guide rod2, and a second pawl32mounted on the sliding member31and matching with the first pawl32. The wrench also includes a toothed block34disposed inside the sliding member31and matching with the guide rod34. The toothed block34has a first position and a second position.

The wrench100is configured such that: when the toothed block34is in the first position, the toothed block34is engaged with the guide rode2, and the toothed block can slide along the guide rod toward the first pawl1, and is locked in the direction away from the first pawl1; when the toothed block34is in the second position, the toothed block34is detached from the guide rod2, and the toothed block34can slide along the guide rod2toward or away from the first pawl.

In an embodiment of the invention, the first position refers to a position where the toothed block34is located when the toothed block34is engaged with the guide rod; the second position refers to a position where the toothed block34is located when the toothed block34and the guide rod2are detached.

As shown inFIG. 2, an engagement portion where the guide rod2is engaged with the toothed block34is provided with unidirectional teeth15having a unidirectional orienting effect: when the sliding member31is pushed toward the first pawl1, the toothed block34is slidable along toothed surface of the unidirectional teeth15, so that the sliding member31and the second pawl32move along the guide rod2and comes close to the first pawl1; when the sliding member31is pushed away from the first pawl2, a sliding movement of the toothed block34along toothed surface of the unidirectional teeth15is obstructed, so that the sliding movement of the sliding member31and the second pawl32along the guide rod2is locked.

As shown inFIG. 3, in the wrench100in the preferred embodiment of the invention, the first pawl1is pivotedly connected to the guide rod2by a fixing pin12, and the second pawl32is fixedly connected to the sliding member31. The first pawl1and the second pawl32are matched for clamping workpieces of different shapes like a pipe fitting, a flat plate, a screw. A first spring13is also arranged between the first pawl1and the guide rod2. The first spring13is a spiral spring. In another embodiment, the first spring13can be replaced with an elastic washer. When the first pawl1and the second pawl32are matched to clamp the workpiece300, the opening of the jaws enables the first pawl to pivot by a small angle along the opposite direction of the arrow A, where the first spring13is compressed, and under the effect of the restoring force, the first spring13pushes the first pawl1along the direction of arrow A, producing pre-tightening force in the workpiece300between the first pawl1and the second pawl32. Because teeth are arranged at the portion where the first pawl1and the second pawl32clamp the workpiece, under the effect of the pre-tightening force, the teeth compress tightly against the surface of the workpiece300, so that the slippage will not occur between the teeth and the wrench100when in a screwing operation.

As shown inFIG. 4, the wrench100includes a guide rod2, a first pawl1, a second pawl32. The guide rod2has a grasp part200, which is a protection sleeve21that can be made of materials of leather, plastic, etc. The shape of the protection sleeve21is ergonomic. The protection sleeve21can be provided to be sheathed on the rod2and can be removed from the guide rod2readily. The protection sleeve21is fixedly connected to the guide rod by a fastener, and preferably, the fastener is a bolt22and a nut26. A hang hole23is arranged on the protection sleeve21. After using the wrench100, the wrench100can be hangingly placed using the hang hole23. Preferably, the protection sleeve21is provided with a second concave part210which is perfectly for embedding the bolt22thereinto, thus on the one hand, the protection sleeve21are made more aesthetic, while in the mean time avoiding the head part of the bolt22hurting the fingers of an operator due to being protruding out of the protection sleeve21.

The first pawl1is pivotedly connected to the guide rod2by the fixing pin12. The fixing pin12is arranged with a snap slot120. A snap ring121is disposed in the snap slot120, such that the fixing pin12will not fall out from inside the mounting holes of the guide rod2and the first pawl1. A first spring13is also arranged between the first pawl1and the guide rod2. As noted above, under the effect of the restoring force of the first spring13, the first pawl1and the second pawl32can produce pre-tightening force in the clamped workpiece when clamping a workpiece, so that slippage will not occur to the wrench100when in screwing operation.

The wrench body100also includes a sliding member31including a first portion310extending along the lower part of the guide rod2toward the first pawl1, the end part thereof, i.e. the portion close to the first pawl1being provided with a slot provided with a second pawl32embedded therein. As shown inFIG. 4, a side of the second pawl32has a clamping surface111matching with the clamping surface110of the first pawl. The two clamping surfaces are both arranged with teeth, and the shapes of the teeth can be identical or partly different. The teeth are used for increasing the friction between the two clamping surfaces and the clamped object. The other side of the second pawl32is provided with a hang tab320embedded in the slot of the first portion310of the sliding member31, and is fixedly connected to the first portion310by the pin321.

The sliding member31also includes a second portion311provided with a cavity312arranged therein. A toothed block34is arranged inside the cavity312. The toothed block34is coupled to the pushbutton33though a connecting rod39. A pin40is used for connection between the connecting rod39and the toothed block34, or the connecting rod39and the pushbutton34. At least two connecting rods39are, parallel to each other, connected to the two sides of the pushbutton33and the toothed block34(seeFIG. 5). The connecting member composed of the pushbutton33, the connecting rod39and the toothed block34is located in the cavity312. The guide rod2passes through the connecting member and meanwhile passes through the second portion311. The connecting rods39are located at the two sides of the guide rod2. The pushbutton33is located at the upper part of the guide rod2and a gap is reserved between the pushbutton33and the guide rod2. The lower part of the guide rod2and the upper surface of the toothed block34are provided with unidirectional teeth15. The upper surface of the toothed block34is engaged with the lower part of the guide rod2. A part of the pushbutton is embedded in the cavity312, and another part is protruding out of the second portion311of the sliding member31.

In a preferred embodiment of the invention, the surface of the pushbutton33is arranged with a first stripes330. Slots parallel to each other are between the first strips330, which, in another embodiment, can also be staggered slots, for increasing the friction between the fingers of the operator and the pushbutton33, and preventing slippage when the fingers of the operator contact the pushbutton33, which tempers using. The two sides of the guide rod2are arranged with recesses24extending across the whole guide rod2, such that, the connecting rods39at both sides of the guide rod2are not in complete contact with the sides of the guide rod2, to facilitate the fast sliding movement of the toothed block34along the guide rod2.

The outside of the second portion311of the sliding member31is provided with a first concave part313which is communicated with the cavity312for embeddingly arranging the coverplate36that fixedly connected to the sliding member31by a screw38. Preferably, the screw38is a flat screw, that is, its end part is flat. A gap is reserved between the end part of the screw38and the toothed block34. A second spring37is arranged between the coverplate36and the toothed block34. The both ends of the spring37are respectively in contact with the toothed block34and the coverplate36(seeFIG. 5). The spring37applied a pressing force to the toothed block34, so that the toothed block34is engaged with the lower part of the guide rod2. Preferably, the second spring37is a compressed spring.

In addition, the outside of the second portion311of the sliding member31is also provided with a thumb abutting part35facilitating the operator to push the sliding member31. The surface of the thumb abutting part35is provided with a second stripes350. Slots parallel to each other are between the second strips350, for increasing the friction between the fingers of the operator and the thumb abutting part35.

FIG. 6-FIG. 9provide perspective views of using wrench100to implement fast adjustment. When the start position of the second pawl32is closed to the grasp part200(seeFIG. 6), the fingers of the operator can contact the thumb abutting part35, and apply a push force to the sliding member31along the direction of arrow B. Since the engaged portion of the toothed block34and the guide rod2is provided with unidirectional teeth15having unidirectional orienting effect, the toothed block34can slide fast along the toothed surface of the unidirectional teeth15toward the direction of arrow B, i.e. the direction of the first claw1. During the sliding movement, the toothed block34compresses downwardly the second spring37, and in return, the second spring37holds up the toothed block34upwardly so that the toothed block34are always in contact with the guide rod2and not detached. The fast sliding movement of the toothed block34toward the first pawl1drives the sliding member31so as to drive the second pawl32to move fast toward the first pawl1, so as to achieve the function of fast reducing the opening of the jaws. If the sliding member31is pushed along the opposite direction of arrow B, i.e., the direction closing to the grasp part200, the sliding movement of the toothed block34along the toothed surface of the unidirectional teeth15is obstructed due to the unidirectional orienting effect of the unidirectional teeth15, the toothed block34thus is locked (seeFIG. 7).

When the start position of the second pawl is closed to the grasp part200, as shown inFIG. 6, the fingers of the operator can also be pushed down on the pushbutton33, i.e., applying pressing force to the pushbutton33, then the pushbutton33presses down the toothed block34through the connecting rod39and simultaneously the toothed block34compresses the second spring37, so that the toothed block34is detached from the guide rod2, and then pushes the sliding member31toward the direction of arrow B, causing the toothed block34to slide fast along the guide rod2and closing to the first pawl1, so as to drive the sliding member31and the second pawl32to move fast toward the first pawl1, realizing the function of fast reducing the opening of the jaws. When the pressing effect to the pushbutton33is cancelled, the toothed block34slide upward and reset due to the effect of the elastic force of the second spring37, so that the toothed block34is engaged with the guide rod2, and at that time the second pawl32stops the movement along the guide rod2.

When the start position of the second pawl32is closed to the first pawl1(seeFIG. 8), the fingers of the operator can be pushed down on the pushbutton33, i.e., applying pressing force to the pushbutton33, then the pushbutton33presses down the toothed block34through the connecting rod39and simultaneously the toothed block34compresses the second spring37, so that the toothed block34is detached from the guide rod2, and then pushes the sliding member31toward the direction of arrow D, causing the toothed block34to slide fast along the guide rod away from the first pawl1and towards the grasp part200, so as to drive the sliding member31and the second pawl32to move fast away from the first pawl1, realizing the function of fast increasing the opening of the jaws. When the pressing effect to the pushbutton33is cancelled, the toothed block34slide upward and reset due to the effect of the elastic force of the second spring37, so that the toothed block34is engaged with the guide rod2, and at that time the second pawl32stops the movement along the guide rod2(seeFIG. 9).FIG. 10provides a perspective view of the wrench in a preferred embodiment of the invention when clamping a workpiece300.FIG. 11is a partial enlarged view ofFIG. 10, showing the angle between the sloping surface314of the sliding member31and the length direction of the guide rod2is a first angle α, the angle between the sloping surface314and the toothed surface152of the unidirectional teeth15being a second angle β, the toothed surface152being the surface obstructing the sliding movement of the toothed block34along the unidirectional teeth15. The angle between the sloping surface314and the connecting rod39is the third angle γ. The side340of the toothed block34sticks tightly to the sloping surface314.

As shown inFIG. 11, when the wrench in the embodiment is clamping the workpiece300, i.e. the wrench being under a stressed condition, the sliding member31applies an upward force perpendicular to the sloping surface314to the toothed block34through the sloping surface314. The force is divided to be a upward branch force perpendicular to the guide rod2and a branch force along the guide rod to the right (i.e. the direction away from the first pawl1), in which the upward branch force perpendicular to the guide rod2enables the toothed block34to be engaged with the guide rod2, and the branch force along the guide rod2to the right enables the toothed block34has a tendency of sliding to the right along the guide rod2. But due to the obstruction effect of the toothed surface152of the unidirectional teeth15, the sliding movement of the toothed block34along the guide rod to the right is obstructed, and, therefore, the toothed block34is locked on the guide rod2. In order for the toothed block34to be better engaged with the guide rod2, the angle α is supposed to be decided depending on the friction coefficient between the sloping surface314and the toothed block34, so as to ensure the toothed block34to be self-locked and maintained in locking position when being subject to force. The angle α is less than 90° and the lesser the better, which is because the lesser the a is, the larger the upward branch force perpendicular to the guide rod2, to which the toothed block34is subject, so that the larger the pressing force to which the unidirectional teeth15are subject, the better the toothed block34is engaged with the guide rod2.

In another aspect, in order to allow realizing reliable locking using friction self-locking between the toothed block34and the sloping surface314, and also realizing fast detachment of the toothed block34and the guide rod2by conquering the friction self-locking between the toothed block34and the sloping surface314when pushing down the pushbutton33. The angle between the connecting rod39and the guide rod2is a fourth angle, which is arranged to be less than 90° and the angle γ between the connecting rod39and the sloping surface314γ is less than 90°, such that when pressing down the pushbutton33, the pushbutton33applies a downward force to the toothed block34through the connecting rod39. The force can be divided to be a branch force perpendicular to the sloping surface314and a downward branch force parallel to the sloping surface314. The smaller the angle γ is, the larger downward branch force to which the toothed block34is subject, and the branch force perpendicular to the sloping surface314is smaller, and the upward friction to which the toothed block34is subject is smaller, and the toothed block34are more readily to conquer the friction to slide downward along the sloping surface314so as to achieve the detachment from the guide rod2and to be unlocked.

In order to ensure the wrench of the invention can still lock the toothed block34and not let it to be detached from the guide rod2when the wrench is under stressed condition and the unidirectional teeth15deform, the angle β between the sloping surface314and the toothed surface152of the unidirectional teeth15is arranged to be more than 0°, and the larger the angle β, the more reliable the locking of the toothed block is. But in the mean time it needs to be rotated by an angle to conquer the locking of the toothed block and the guide rod brought by the angle β, so as to detach the teeth on the toothed block34and the teeth on the guide rod2. Therefore a certain space316is required to be reserved between the sliding member31and the cavity in the cavity312to allow the toothed block34to rotate in the cavity312so as to detach the teeth of the two. Meanwhile, the reserve space316can also ensure the plurality of the teeth on the toothed block34to automatically find position and reliably come into contact with the guide rod2so as to increase the strength between the teeth.

In a preferred embodiment of the invention, α=45°, β=15°, γ=40°.

The foregoing described the preferred embodiments of the present invention. It should be understood that an ordinary one skilled in the art can make many modifications and variations according to the concept of the present invention without creative work. Therefore, any person skilled in the art can get any technical solution through logical analyses, deductions and limited experiments, which should fall in the protection scope defined by the claims.