Hydraulic Torque Wrench

Abstract

A hydraulic torque wrench (10) is provided that includes: a head (11) having an input for pressurized hydraulic fluid; a rotatable connector for coupling to an object to be rotated by the hydraulic torque wrench (10); and a drive mechanism (12) driven by hydraulic fluid introduced at the input and causing rotation of the rotatable coupling. A reaction arm (1) is attached to the head (11) via a mount (16) that selectively allows rotational movement of the reaction arm (1) relative to the head (11) about an axis, the reaction arm (1) being positioned to react against a surface when the drive mechanism (12) rotates the rotatable coupling. Here, the mount (16) comprises: a splined connection with complementary splines (20) on the head (11) and the reaction arm (1) that permits linear movement of the reaction arm (1) relative to the head (11) along an axis from a first position in which the splines (20) of the splined connection engage with each other to prevent relative rotation of the reaction arm (1) and the head (11) and a second position in which the splines (20) of the splined connection do not engage with each other and relative rotation of the head (11) and the reaction arm (1) is permitted; and a rotational movement limiter that limits the relative rotational movement of the reaction arm (1) and the head (11). The possibility of unanticipated, unnecessary or undesirable separation of the reaction arm (1) and the head (11) is reduced.

Description

[Technical field]

[0001] The present invention relates to a hydraulic torque wrench. [Background technology]

[0002] Torque wrenches, such as hydraulic torque wrenches, are well known in the art and are widely used, for example, to apply torque to nuts, bolts, or other fasteners.

[0003] Some hydraulic torque wrenches, such as that disclosed in WO 2018 / 130854, comprise a head including a drive mechanism powered by hydraulic fluid to drive a rotating object, and a reaction arm that provides reactive support for the torque wrench when in operation. For operational flexibility reasons, it is desirable to be able to change the orientation of the reaction arm relative to the head.

[0004] WO 2018 / 130854 discloses a solution in which a splined connection allows the head and reaction arm to be separated and reconnected at a different angular position. However, such a solution still presents a number of problems. Firstly, once the head and reaction arm are separated, there is nothing to stop one part. Considering that hydraulic torque wrenches are frequently used in situations where work is carried out at height, such as on wind turbines, this represents a fall accident potentially resulting in loss of tool parts and danger to those below the user, as well as danger to any equipment in the path of the falling parts. Prior art designs typically include latches or the like to hold the parts together, but such latches can fail during use, leading to unexpected separation or unstable tool positioning.

[0005] Second, while a spline connection allows a user to join two parts in any number of positions, the number of positions in which the tool will desirably operate is much smaller, typically with the reaction arm either in line with the head or offset at 90 degrees. The inventors have realized that it is easy for a user to join two parts one or two splines away from the desired position, resulting in a non-ergonomic use position that is potentially dangerous if the positioning is unstable and the tool moves in an unpredictable and unpredictable manner during use. Summary of the Invention [Means for solving the problem]

[0006] According to a first aspect of the present invention, we have provided a hydraulic torque wrench comprising: a head having an input for pressurized hydraulic fluid, a rotatable connector for coupling to an item to be rotated by a hydraulic torque wrench, and a drive mechanism actuated by hydraulic fluid introduced at the input and causing the rotatable coupling to rotate; and a reaction arm attached to the head via a mount that selectively permits rotational movement of the reaction arm relative to the head about an axis, the reaction arm being positioned to react against the surface when the drive mechanism rotates the rotatable coupling; A hydraulic torque wrench comprising: Mounts include: a spline connection with complementary splines on the head and the reaction arm that permit linear movement of the reaction arm relative to the head along an axis from a first position in which the splines of the spline connection interengage to prevent relative rotation of the reaction arm and the head, and a second position in which the splines of the spline connection do not interengage and relative rotation of the head and the reaction arm is permitted; and a linear movement limiter preventing linear movement of the reaction arm relative to the head beyond the second position; and at least one biasing member operative to bias the reaction arm toward the first position. A hydraulic torque wrench is provided.

[0007] As such, this represents a hydraulic torque wrench in which the reaction arm and head are unlikely to separate unexpectedly, unnecessarily, or undesirably. A user must operate against the bias of the biasing member to move the reaction arm to the second position, which means that the reaction arm will tend to remain in the first position where the head and reaction arm are unlikely to separate. Even if a user unexpectedly lets go of the reaction arm in the second position, the reaction arm will tend to return to the first position rather than falling.

[0008] Typically the biasing member may comprise a spring.The linear travel limiter may comprise at least one bolt having a stud and a head, the stud of each bolt being fixed relative to one of the head and the reaction arm and acting within an aperture in the other of the head and the reaction arm, the head being too large to pass through the aperture so as to limit the linear travel.

[0009] The mount may further comprise a rotational movement limiter, which may limit the relative rotational movement of the reaction arm and the head. Typically, the movement limiter may limit the movement to a certain range. This range may typically be up to 270 degrees, 180 degrees or 90 degrees, and may be 90 degrees or 180 degrees. The end points of the range may then represent the desired positions of the reaction arm relative to the head (typically the vertical and horizontal positions of the reaction arm, or two horizontal positions 180 degrees apart), thus aiding the user in locating these positions. The rotational movement limiter may comprise a protrusion, such as a pin or screw, on one of the head and reaction arm that functions in a slot or groove on the other of the head and reaction arm, which typically has ends that define the range.

[0010] The hydraulic torque wrench may also include at least one indicia that indicates a desired relative rotational position of the reaction arm with respect to the head.

[0011] The mount may further include a retention mechanism for selectively locking the head and reaction arm relative to one another when in the first position, which may include, for example, a latch or push button lock and act to lock the complementary splines relative to one another.

[0012] According to a second aspect of the present invention, we have provided a hydraulic torque wrench comprising: a head having an input for pressurized hydraulic fluid, a rotatable connector for coupling to an item to be rotated by a hydraulic torque wrench, and a drive mechanism actuated by hydraulic fluid introduced at the input and causing the rotatable coupling to rotate; and a reaction arm attached to the head via a mount that selectively permits rotational movement of the reaction arm relative to the head about an axis, the reaction arm being positioned to react against the surface when the drive mechanism rotates the rotatable coupling; A hydraulic torque wrench comprising: Mounts include: a spline connection with complementary splines on the head and the reaction arm that permit linear movement of the reaction arm relative to the head along an axis from a first position in which the splines of the spline connection interengage to prevent relative rotation of the reaction arm and the head, and a second position in which the splines of the spline connection do not interengage and relative rotation of the head and the reaction arm is permitted; and Rotational movement limiter for limiting the relative rotational movement of the reaction arm and head A hydraulic torque wrench is provided.

[0013] This allows the limits to represent desired positions of the reaction arm relative to the head (typically the vertical and horizontal positions of the reaction arm, or two horizontal positions 180 degrees apart), thus assisting the user in locating these positions.

[0014] The hydraulic torque wrench may have any of the optional features of the first aspect of the invention. The mount may include a linear travel limiter that prevents linear movement of the reaction arm relative to the head beyond the second position. The mount may also include at least one biasing member that acts to bias the reaction arm towards the first position.

[0015] According to a third aspect of the present invention there is provided a hydraulic torque wrench comprising: a head having an input for pressurized hydraulic fluid, a rotatable connector for coupling to an item to be rotated by a hydraulic torque wrench, and a drive mechanism actuated by hydraulic fluid introduced at the input and causing the rotatable coupling to rotate; and a reaction arm attached to the head via a mount that selectively permits rotational movement of the reaction arm relative to the head about an axis, the reaction arm being positioned to react against the surface when the drive mechanism rotates the rotatable coupling; A hydraulic torque wrench comprising: Mounts include: a spline connection with complementary splines on the head and the reaction arm that permit linear movement of the reaction arm relative to the head along an axis from a first position in which the splines of the spline connection interengage to prevent relative rotation of the reaction arm and the head, and a second position in which the splines of the spline connection do not interengage and relative rotation of the head and the reaction arm is permitted; and a linear travel limiter for preventing linear movement of a reaction arm relative to a head beyond a second position, the linear travel limiter comprising a rigid elongated member attached to the head, a step in the reaction arm engaging a stop in the rigid elongated member to stop linear movement beyond the second position; A hydraulic torque wrench is provided.

[0016] Typically, the rigid elongated member acts on a bore in the reaction arm; the bore and the rigid elongated member may each have a length, the bore may have a diameter, and the rigid elongated member may have a width. The diameter and width may vary along the length, and both the diameter and width may be perpendicular to the length. The step may comprise a change in diameter of the bore, while the stopper may comprise a portion of the rigid elongated member that is wider than the remainder of the rigid elongated member.

[0017] Typically, the rigid elongated member may comprise a bolt secured to a head, with a portion of the rigid elongated member being wider than the remainder of the rigid elongated member to form the head of the bolt.

[0018] The splines on the head may be provided on a cylindrical boss extending outwardly from a base on the head. The rigid elongate member may be attached to the head at or adjacent the base.

[0019] This configuration is reliable and easy to manufacture.

[0020] The hydraulic torque wrench may have any of the features according to the first or second aspects of the invention. The mount may include a rotational movement limiter for limiting relative rotational movement of the reaction arm and the head. It may also include at least one biasing member acting to bias the reaction arm towards the first position.

[0021] Description of embodiments of the present invention will now be given, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0022] [Figure 1-4] 1 to 4 are side views of a hydraulic torque wrench according to an embodiment of the present invention in first to fourth positions, respectively. [Diagram 5] FIG. 5 shows a cross section taken along line DD in FIG. [Figure 6] FIG. 6 shows a rear view of the hydraulic torque wrench of FIG. 1 in a first position. [Figure 7] FIG. 7 shows a cross section taken along line JJ in FIG. [Figure 8] FIG. 8 shows the same cross section as in FIG. 6, but with the torque wrench in the second position shown in FIG. [Figure 9] FIG. 9 shows a cross section taken along line LL in FIG. [Figure 10] FIG. 10 shows the same cross section as in FIG. 9, but with the torque wrench in the third position shown in FIG. [Figure 11] FIG. 11 shows a cross section taken along line AA in FIG. [Figure 12] FIG. 12 shows a perspective view of the hydraulic torque wrench of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] A hydraulic torque wrench 10 is shown in the accompanying drawings. Wrench 10 comprises a head 11 having a port 12 for hydraulic fluid. Head 11 contains a drive mechanism (mainly internal, but shown at 13) which uses the pressure of pressurized hydraulic fluid at port 12 to rotate a square drive 14. This is then coupled to the item to be rotated (e.g. via a socket to a nut).

[0024] The hydraulic torque wrench 10 also comprises a reaction arm 1, which is used to support the hydraulic torque wrench against reaction forces when rotating an object to be rotated. Typically, the reaction surface 15 of the arm is positioned against a convenient surface such that the reaction surface 15 is capable of supporting the hydraulic torque wrench.

[0025] The reaction arm 1 is attached to the head 11 via a mount 16. It comprises a splined cylindrical member 1 having splines 20 extending from the head 11 which engage complementary splined bores 18 with splines 21 in the reaction arm 1. When the two sets of splines 20, 21 are engaged in a first position of the hydraulic torque wrench shown in FIG.

[0026] The mount further comprises an anchor 2. As can be seen in Figure 11 of the accompanying drawings, the three dowel screws 6 in the anchor 2 are arranged tangentially to a circumferential groove 19 in the non-splined portion of the cylindrical member 17. This allows the anchor 2 to rotate (with the effect of splines 20, 21) but not to move linearly relative to the head 11.

[0027] Two elongated rigid bolts 3a, 3b are fixed to the anchor but pass through bores 22a, 22b in the reaction arm 1. Each bolt 3a, 3b has a head 23a, 23b; the bores 22a, 22b are wider than the heads 23a, 23b but have progressively smaller diameters 24a, 24b.

[0028] Bolt 3a is short; so that pulling reaction arm 1 linearly from head 11 from the first position of Figures 1 and 7 to the second position of Figures 2 and 8 will cause head 23a of bolt 3a to abut step 24a and stop further movement as in Figures 2 and 8. This stop in linear movement corresponds to disengagement of splines 20, 21.

[0029] The bolt 3b is long and has a compression spring 25 acting within the bore between the step 24b and the head 23b, so that the spring 25 acts to urge the splines 20, 21 back into engagement, returning the mount to the first position of FIG.

[0030] Therefore, when a user wishes to change the position of the reaction arm 1, starting from the first use position shown in Figure 1, he pulls the reaction arm 1 back against the force of the spring 25 so that the splines 20, 21 disengage. The wrench is therefore now in the second position shown in Figure 2.

[0031] At this point, the user is able to rotate the reaction arm 1 relative to the head 11. However, the cylindrical member 17 is provided with a circumferential groove 8, which extends slightly more than 180 degrees around the circumference of the cylindrical member 11. The screw 7 in the anchor 2 extends into this groove 8. The screw therefore limits the rotational movement involving the reaction arm 1 relative to the head 11; taking into account the diameter of the screw, the rotational movement is limited to 180 degrees. The ends of the groove 8 represent the positions normally used, where the reaction arm 1 extends perpendicular to the head 11, one of which is shown in Figures 3 and 4. The midpoint of the groove 8 represents the other normally used position (shown in Figures 1 and 2 of the drawings), where the reaction arm 1 is aligned with the head 11.

[0032] This limitation on the rotational movement of reaction arm 1 relative to head 11 allows the user to easily find the two most commonly used positions; the likelihood of error being one or two spline spaces from the desired position is significantly reduced, making the wrench more reliable to install.

[0033] As shown in FIG. 12 of the accompanying drawings, the midpoint position of FIG. 1 can be indicated by a mark 26 on the anchor 2, thus enabling the user to easily find other commonly used positions.

[0034] Thus, the user has now selected the desired new alignment of the reaction arm 1 and head 11, with the wrench in the third position shown in Figure 3 of the accompanying drawings. The user can then, with the force from the spring 25 and his own applied force, guide the splines 20, 21 back into engagement so that the wrench is in the fourth position shown in Figure 4. A push button lock 5 is provided to hold the reaction arm 1 and head 11 in position relative to one another; the user can then actuate this and the wrench is ready for use. Should this lock 5 fail or be accidentally disengaged, the biasing force of the spring 25 and the restriction to movement by the bolt 3a will tend to keep the wrench in the engaged position without it disintegrating as may be the case with prior art devices.

Claims

1. 1. A hydraulic torque wrench comprising: a head having an input for pressurized hydraulic fluid, a rotatable connector for coupling to an item to be rotated by the hydraulic torque wrench, and a drive mechanism actuated by hydraulic fluid introduced at the input and causing the rotatable coupling to rotate; and a reaction arm attached to the head via a mount that selectively permits rotational movement of the reaction arm relative to the head about an axis, the reaction arm being positioned to react against a surface when the drive mechanism rotates the rotatable coupling; A hydraulic torque wrench comprising: The mount: a spline connection comprising complementary splines on the head and the reaction arm, the spline connection permitting linear movement of the reaction arm relative to the head along the axis from a first position in which the splines of the spline connection interengage to prevent relative rotation of the reaction arm and the head, and a second position in which the splines of the spline connection do not interengage, allowing relative rotation of the head and the reaction arm; and a rotational movement limiter that limits the relative rotational movement of the reaction arm and the head; A hydraulic torque wrench.

2. 1. A hydraulic torque wrench comprising: a head having an input for pressurized hydraulic fluid, a rotatable connector for coupling to an item to be rotated by the hydraulic torque wrench, and a drive mechanism actuated by hydraulic fluid introduced at the input and causing the rotatable coupling to rotate; and a reaction arm attached to the head via a mount that selectively permits rotational movement of the reaction arm relative to the head about an axis, the reaction arm being positioned to react against a surface when the drive mechanism rotates the rotatable coupling; A hydraulic torque wrench comprising: The mount: a spline connection comprising complementary splines on the head and the reaction arm, the spline connection permitting linear movement of the reaction arm relative to the head along the axis from a first position in which the splines of the spline connection interengage to prevent relative rotation of the reaction arm and the head, and a second position in which the splines of the spline connection do not interengage, allowing relative rotation of the head and the reaction arm; and a linear travel limiter for preventing linear movement of the reaction arm relative to the head beyond the second position, the linear travel limiter comprising a rigid elongated member attached to the head, a step on the reaction arm engaging a stop on the rigid elongated member to stop the linear movement beyond the second position; A hydraulic torque wrench.

3. 1. A hydraulic torque wrench comprising: a head having an input for pressurized hydraulic fluid, a rotatable connector for coupling to an item to be rotated by the hydraulic torque wrench, and a drive mechanism actuated by hydraulic fluid introduced at the input and causing the rotatable coupling to rotate; and a reaction arm attached to the head via a mount that selectively permits rotational movement of the reaction arm relative to the head about an axis, the reaction arm being positioned to react against a surface when the drive mechanism rotates the rotatable coupling; A hydraulic torque wrench comprising: The mount: a spline connection comprising complementary splines on the head and the reaction arm, the spline connection permitting linear movement of the reaction arm relative to the head along the axis from a first position in which the splines of the spline connection interengage to prevent relative rotation of the reaction arm and the head, and a second position in which the splines of the spline connection do not interengage, allowing relative rotation of the head and the reaction arm; and a linear movement limiter that prevents linear movement of the reaction arm relative to the head beyond the second position, and at least one biasing member that acts to bias the reaction arm toward the first position. A hydraulic torque wrench.

4. 2. The hydraulic torque wrench of claim 1, wherein the mount includes a linear travel limiter that prevents linear movement of the reaction arm relative to the head beyond the second position.

5. 5. The hydraulic torque wrench of claim 4, wherein said mount includes at least one biasing member acting to bias said reaction arm toward said first position.

6. 4. A hydraulic torque wrench according to claim 2 or 3, wherein the mount comprises a rotational movement limiter that limits relative rotational movement of the reaction arm and the head.

7. 6. A hydraulic torque wrench according to any one of claims 3 to 5, wherein the linear travel limiter comprises at least one bolt having a stud and a head, the stud of each bolt being fixed relative to one of the head and the reaction arm and functioning within an aperture in the other of the head and the reaction arm, the head being too large to pass through the aperture so as to limit the linear travel.

8. 2. The hydraulic torque wrench of claim 1, wherein said rotational travel limiter limits said travel to a fixed range.

9. 9. The hydraulic torque wrench of claim 8, wherein the range is up to 270 degrees, 180 degrees, or 90 degrees.

10. 10. The hydraulic torque wrench of claim 9, wherein the range is 90 degrees or 180 degrees.

11. A hydraulic torque wrench according to any one of claims 8 to 10, wherein the endpoints of a range represent desired positions of the reaction arm relative to the head.

12. 11. A hydraulic torque wrench as claimed in any one of claims 1 or 8 to 10, wherein the rotational travel limiter comprises a protrusion on one of the head and the reaction arm acting in a slot or groove or groove in the other of the head and the reaction arm, the slot or groove typically having ends which define the extent.

13. A hydraulic torque wrench according to any one of claims 1 to 3, comprising at least one marking indicating a desired relative rotational position of the reaction arm with respect to the head.

14. A hydraulic torque wrench according to any one of claims 1 to 3, comprising a retention mechanism for selectively locking the head and reaction arm together when in the first position.

15. the rigid elongated member operates in a bore in the reaction arm; the bore and the rigid elongated member each have a length, the bore has a diameter, and the rigid elongated member has a width; A hydraulic torque wrench according to any preceding claim, wherein the step comprises a change in diameter of the bore and the stop comprises a portion of the rigid elongated member that is wider than the remainder of the rigid elongated member.

16. 16. The hydraulic torque wrench of claim 15, wherein the splines on the head are mounted on a cylindrical boss extending outwardly from a base on the head, and the rigid elongated member is attached to the head at or adjacent the base.

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