WO2005065890A1

WO2005065890A1 - Ratchet wrench and fastener therefor

Info

Publication number: WO2005065890A1
Application number: PCT/SE2005/000001
Authority: WO
Inventors: Gunnar Kemppainen
Original assignee: Gunnar Kemppainen
Priority date: 2004-01-02
Filing date: 2005-01-03
Publication date: 2005-07-21
Also published as: SE527594C2; SE0400001D0; SE0400001L

Abstract

A ratchet wrench (10) for driving a rotatable fastener (60), comprising a handle (20), a gripping means (30) for the fastener at an end of the handle (20) and a ratchet means (50) on the gripping means (30) adapted for engagement with the fastener (30) in a driving direction (R) and for disengagement from the fastener in a an opposite direction thereto. The gripping means (30) has a pair of jaws, a first jaw (32) of which being pivotably supported on the handle (20) between an open gripping position for enclosing and releasing the fastener (60) and a closed gripping position (D) for rotatably driving the fastener (60). The gripping means (30) has also guiding means (40) for cooperation with guiding means (70) on the fastener (60) to locate the gripping means in an axial position around the fastener in the closed gripping position. The invention also relates to a fastener (60) for the ratchet wrench

Description

Ratchet wrench and fastener therefor

TECHNICAL FIELD

This invention relates to a ratchet wrench for driving a rotatable fastener, comprising a handle, a gripping means for the fastener at an end of the handle, and a ratchet means on the gripping means adapted for engagement with the fastener in a driving direction and for disengagement from the fastener in a an opposite direction thereto.

BACKGROUND

A hose joint having a fixed wrench ratchet according to the principle mentioned above, is known from SE-B-340 918. While this ratchet wrench is easy to handle, it has the disadvantage of not being releasable from the hose joint without disassembling the hose joint.

SUMMARY OF THE INVENTION

An object of the present invention is to further develop a ratchet wrench of the kind described above that is capable of being easily mounted around the fastener and easily removed from the fastener.

This is obtained by the features of the appended claims.

According to an aspect of the invention, the gripping means comprises a pair of jaws, a first jaw being pivotably supported on the handle between an open gripping position for enclosing and releasing the fastener and a closed gripping position for rotatably driving the fastener, and guiding means on the gripping means for cooperation with guiding means on the fastener to locate the gripping means in an axial position around the fastener in the closed gripping position.

In one embodiment, the ratchet wrench also has a second jaw which is supported on the handle pivotable to the open gripping position in the same pivoting direction as the first jaw. By the jaws, in this manner, rotate in the same direction between the open and closed gripping positions, the gripping means can be designed to be very easily opened and closed. The guiding means of the gripping means consists of the flat faces of the jaws which in one embodiment are guided in an annular groove between teeth in the fastener. In another embodiment, flat inner faces of the jaws guide the gripping means around the outer faces of a set of teeth.

If the spaces between the teeth of the fastener has such a length that they allow a certain free angular movement of the gripping means, the ratchet wrench can drive the fastener by impact action in a manner comparable to a slide hammer. To strengthen this impact action the ratchet wrench may have a massive handle grip.

Other features and advantages of the invention will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a ratchet wrench and a fastener according to the invention; FIG. 2 A-D show the ratchet wrench according to FIG. 1 during different stages in a typical course of gripping a fastener;

FIG. 3 shows the ratchet wrench according to FIG. 1 including an enlarged area of the ratchet means of the ratchet wrench.

FIG. 4 shows the ratchet wrench according to FIG. 1 including a diagrammatically indicated massive handle grip;

FIG. 5 shows a ratchet wrench having an alternatively designed ratchet means; FIG. 6 is a lateral broken away view in a larger scale of the wrench shown in FIG. 5; FIG. 7 is a view corresponding to FIG. 6 showing another alternatively designed ratchet means; FIG. 8 shows a ratchet wrench according to the invention having an alternatively designed gripping means in an open position; and

FIG. 9 shows the ratchet wrench of FIG. 8 with the gripping means in a closed position and showing in an enlarged area the ratchet means of the wrench.

DETAILED DESCRIPTION OF ENBODOMENTS

The ratchet wrench generally designated by 10 in FIG.1-7 has a handle 20, and a gripping means 30 connected to the handle and including a first jaw 32 and a second jaw 42. The handle 20 is assembled by a pair of handle shanks 22 holding the jaws 32, 42 therebetween through first and second pivot joints 24 and 26, respectively. The first pivot joint 24 is located a distance further in on the handle 20 than the second pivot joint 26. The first jaw 32 therefore has an elongate pivot arm 36 ending in a hook-shaped gripping member 34 having a semi-circular opening. The second jaw 42 has a gripping member 44 that also has a semi-circular opening as well as a lever arm 46 on the other side of the second pivot joint 26.

As is apparent particularly from FIG. 5, in a closed gripping position of the gripping means 30, the second jaw 42 is situated in an end position by virtue of the lever arm 46 resting against the pivot arm 36 of first jaw 30 at the pivot joint 24. Accordingly, from this end position, the second jaw 42 may now be turned only in the direction of arrow R of FIG. 5. If a user now wishes to open the gripping means 30, the user needs only, by the same hand that holds the handle 20, to force the outside of the gripping member 44 of second jaw 42 against an object to be loosened tightened by the wrench, for example a fastener 60 according to the invention. Thereby, the second jaw 42 will be turned in the direction R and bring the first jaw 32 into a beginning opening movement. The user can now force the outside of the gripping member 34 of the first jaw 32 against the fastener 60 until the gripping means attains an open position corresponding to that shown in FIG. 1.

The gripping member 34 of the first gripping means 32 can now be hooked onto the fastener 60 by its substantially semi-circular interior side according to FIG. 2A. In order to close the gripping means, the user manipulates the handle 20, for example pulls the handle towards the user, such that the first jaw 32 starts to turn back around the joint 24 (FIG. 2B). When, according to FIG. 2C, the gripping means is coming close to its closed position, the semi-circular interior side of the second claw 42 makes contact with the fastener 60 and is guided towards the fastener during the continuing turning-back movement of the jaw 32 such that both jaws 32, 42 can fully enclose the fastener in the manner shown in FIG. 2D.

By the gripping member 34 of the first jaw 32 being hook-shaped, the user is also able to use the ratchet wrench to lift or pull for example the hose and the coupling that is comprised by the fastener 60 itself, without the danger that the gripping means 30 is unintentionally opened. When needed, the gripping means 30 may, however, also be provided with a locking device to be later described for the closed position.

In order to open the gripping means the user needs to turn the handle 20 - and/or the first jaw 32 - in an opposite direction. As will be understood when studying the reverse course of movement from FIG. 2D to FIG. 2A, to open the gripping means to the position shown in FIG. 2A, it is sufficient if the user, by a slight wrist movement, exerts a torque in the opening direction to the pivot joint 24 and thereafter or simultaneously pushes the handle 20 away from the user.

According to the invention, the fastener 60 (FIG. 1) has a guide, generally designated by 70, for the gripping means 30 of the ratchet wrench 10, for securely retaining the closed gripping means 30 in place when rotationally driving the fastener 60. Typically but not necessarily, the fastener 60 is an internally threaded connector nut of the kind included in a releasable hose joint of a known type not shown in the drawing and used for fluid-tight interconnection of a pair of hose ends.

In the embodiment shown on FIGS. 1-7, the guide 70 consists of a peripheral exterior groove in the fastener 60. The groove 70 is intended to receive the interior side 38 of the gripping means 30 in such a manner that the internal lateral faces 72 of the groove engage guidingly with external lateral faces 40 (FIG. 5) of the gripping means 30.

To obtain the ratchet function of the wrench, between the gripping means 30 and the fastener 60, a ratchet coupling of a type known per se and comprising drive teeth 64 and teeth spaces 66 on the fastener for cooperation with a ratchet member in the shape of a pawl 52 of a ratchet coupling means 50 on the gripping means 30. The pawl 52 is adapted to exert a resilient force against the teeth/spaces and has such a profile that it is arrested against the teeth 64 in a driving direction, and is pushed back by the teeth 64 to slide over these in a non-driving opposite rotational direction when the user turns the ratchet wrench 10 back around the fastener 60.

As is apparent from the drawing, the ratchet coupling means 50 may have different configurations. In the embodiment according to FIGS. 1 - 4, the coupling means 50 has a pawl 52 dis- placeably guided against spring force. In the embodiments according to FIGS. 5, 6, 8, 9 the ratchet coupling means 50 is shaped as a lever or a pivot arm supported by a pivot joint 54 and is forced by a spring 56 towards the fastener 60; a stop 59 (FIG. 9) may be provided to prevent excessive outward pivotal movement of the pawl 52 of lever 50.

The alternative ratchet coupling means 50 of the embodiment of FIG. 7 instead comprises a pawl 52 arranged approximately as a freewheel coupling and guided, for example, in a groove 58 converging to the fastener. In the example of FIG. 7 the pawl 52 has a circular cylindrical shape and is optionally prevented to rotate freely, for example by a toothing indicated in the groove 58, when it is in engagement with the fastener 60. By such a ratchet coupling means 50 the fastener may have an engagement profile different from that already described having driv- ing teeth and teeth spaces, for example the shown polygonal shape as in a conventional nut, or even a pure circular profile as indicated in phantom in FIG. 7.

Although not shown on the drawing, when needed, more than one ratchet coupling means 50 may be provided on the gripping means to distribute the forces when driving the fastener 60.

When studying FIG. 5 it will appreciated that in the driving rotational direction R of ratchet wrench 10, i.e. when the user exerts a force F to the handle of FIG. 5, the jaws 32 and 42 will retain the gripping means 30 in its closed position. In order not to danger the gripping means 30 to open when the wrench is turned back in the opposite non-driving direction, it may be sufficient if the friction in either or both joints 24, 26 is so large that the small resistance against the turn back movement, which is exerted, on the one hand, by the friction between the gripping means 30 and the fastener 60 and, on the other hand, by the ratchet means 50 when it is pushed back by the teeth 64 of fastener 60, is not capable of opening the gripping means 30. It is also easy for the user to exert a small torque m on the handle by his/her wrist, which torque tends to keep the gripping means 30 closed, at the same time as the user by a movement of his/her arm turns the wrench 10 back by a small force f. During severe conditions, for example when divers are working with large hose couplings at large depths in sea, it may, however, be convenient to provide the second jaw with a locking device 14 (FIG. 4) that prevents the gripping means 30 from being unintentionally opened. While other solutions are possible, in the example shown, the locking device comprises a catch 14 which is displaceable, for example, by the thumb of the user and which in its forwardly displaced arresting position is in engagement with the free end of the lever arm 46 of the second jaw 42 and arrests second jaw 42 in its closed position

As is further indicated in phantom in FIG. 4, the handle 20 may be provided with a massive hand grip 12. The massive hand grip 12 is capable of increasing a in impact action when the wrench is used in a manner comparable to a slide hammer, i.e. when the user uses the play formed by the spaces 66 between the teeth 64 of the fastener 60 to accelerate the ratchet wrench 10 in the drive direction R so that the pawls 52 of the ratchet means 50 exert an impact action on engagement edges of the teeth 64

To further increase the impact action, the teeth spaces 66 should have a peripheral extension, as large as possible Sufficiently wide teeth spaces 66 may be obtained if the fastener 60, as shown for example in FIG. 1 , is provided with five teeth 66 in each row around the fastener 60 FIG. 8 and 9 show an alternative embodiment of an ratchet wrench 10 and fastener 60. In this case the ratchet coupling may be regarded as reversely configured such that the fastener 60 has only one annular row of drive teeth 64, while the gripping members 34, 44 of gripping means 30 are shaped double-walled to define an annular groove therebetween in the closed position of the gripping means 30. The lateral opposing internal faces 40 of the groove acts like a guide for the external lateral faces 72 facing away from each other on the annular row of drive teeth 64

Claims

1. A ratchet wrench (10) for driving a rotatable fastener (60), comprising a handle (20); a gripping means (30) for the fastener at an end of the handle (20); and a ratchet means (50) on the gripping means (30) adapted for engagement with the fastener (30) in a driving direction (R) and for disengagement from the fastener in a an opposite direction thereto; the gripping means (30) comprising a pair of jaws , a first jaw (32) being pivotably supported on the handle (20) between an open gripping position (A) for enclosing and releasing the fastener (60) and a closed gripping position (D) for rotatably driving the fastener (60), and guiding means (40) on the gripping means (30) for cooperation with guiding means (70) on the fastener to locate the gripping means in an axial position around the fastener in the closed gripping position (D).

2. The ratchet wrench according to claim 1 , wherein also a second jaw (42) is supported on the handle (20) pivotable to the open gripping position (A) in the same direction as the first jaw (32).

3. The ratchet wrench according to claim 2, wherein the first jaw (32) is pivotable around a pivot joint (24) located further in from said end of the handle (12) than a pivot joint (26) for the second jaw (42).

4. The ratchet wrench according to claims 2 or 3, wherein the second jaw (42) has a lever arm (34) by means of which it is capable of being locked to the handle (20).

5. The ratchet wrench according to any of the previous claims, wherein said guiding means of the gripping means (30) comprises opposite lateral faces (40) on the gripping means (32) and wherein said guiding means of the fastener (60) comprises opposite lateral faces (72) on the fastener (60).

6. The ratchet wrench according to claim 5, wherein the lateral faces (40) of the gripping means (30) are facing away from each other and the lateral faces (72) of the fastener (60) are facing to each other.

7. The ratchet wrench according to claim 6, wherein the ratchet coupling (50) is adapted for engagement with the lateral faces (72) of the fastener (60) on both sides exteriorly of the lateral faces (40) of the gripping means.

8. The ratchet wrench according to claim 5, wherein the lateral faces (40) of the gripping means (30) are facing to each other and the lateral faces (72) of the fastener (60) are facing away from each other.

9. The ratchet wrench according to claim 8, wherein the ratchet coupling (50) is adapted for engagement with raised portions (64) between the lateral faces (72) of the gripping means.

10. The ratchet wrench according to any of the previous claims, comprising a massive handle grip (12) adapted to provide an impact action when driving fasteners having teeth spaces with a peripheral extension (66) between driving teeth (64) that allows free acceleration of the massive handle grip (12).

11. A fastener (10) for a ratchet wrench (60) according to any of the previous claims and provided with guiding means (72) comprising lateral faces of a peripheral groove or a peripheral raised portion of the fastener (60), said lateral faces defining drive teeth (64) for the ratchet wrench (10).

12. The fastener according to claim 12, wherein spaces (66) between the teeth (64) have a peripheral extension that allows a free acceleration for impact action when driving the fastener.