tool

Abstract

A drive (11) assembly (10) for a torque wrench (1), the drive (11) assembly (10) including: a ratchet (14) having internal splines (13a; 14a); a drive (11) including a shaft (11b) arranged to be removably received within the ratchet (14), the shaft (11b) having external splines (11a) passing through the ratchet (14) and arranged to mesh with the splines of the ratchet (14) such that rotation of the ratchet (14) rotates the shaft (11b); and a drive sleeve (13) arranged to seat on the ratchet (14) and having internal splines (13a; 14a) that match the internal splines (13a; 14a) of the ratchet (14). The drive sleeve 13 and the ratchet 14 include cooperating features arranged to prevent relative rotation of the drive sleeve 13 and the ratchet 14 when the drive sleeve 13 is seated on the ratchet 14. Ease of use of the tool can be improved.

Description

[Technical field]

[0001] FIELD OF THEINVENTION This invention relates to tools, and particularly, but not exclusively, to drive assemblies for tools such as hydraulic wrenches. [Background technology]

[0002] Torque wrenches, such as hydraulic torque wrenches, are well known in the art and are widely used, for example, for applying torque to nuts, bolts, or other fasteners. Atlas Copco, as well as other suppliers, offer hydraulic torque wrenches with a removable drive (typically a square drive, but different shaped drives may be used, e.g., hexagonal or socket drives). One or more drive sleeves may be used to aid in inserting and / or positioning the drive. One or more removable retainers may be used to hold the drive and drive sleeve in place.

[0003] To reverse the direction of rotation, it is necessary to remove the square drive component and position it on the opposite side of the tool. When changing the drive direction, the operator must simultaneously handle several components, particularly the wrench, the square drive (and socket), and one or more retainers. The retainers can easily be dropped and lost, potentially making the tool dangerous or unstable and resulting in other components becoming misaligned. In particular, the drive sleeve can rotate freely once the square drive is removed. Generally, the operator is required to manually realign the drive sleeve in order to reinsert the drive from the opposite side of the tool. The same considerations apply when replacing a drive (e.g., for a different shape or size, or in the case of excessive wear).

[0004] It is desirable to improve the ease of use of tools. Summary of the Invention [Means for solving the problem]

[0005] According to a first aspect of the present invention there is provided a drive assembly for a torque wrench comprising: Ratchet with internal splines; a drive comprising a shaft arranged to be removably received within the ratchet, the shaft passing through the ratchet and having external splines arranged to mesh with the splines of the ratchet such that rotation of the ratchet rotates the shaft; and A drive sleeve positioned to seat on the ratchet and having internal splines that match the internal splines of the ratchet. Equipped with.

[0006] The drive sleeve and the ratchet include cooperating features arranged to prevent relative rotation of the drive sleeve and the ratchet when the drive sleeve is seated on the ratchet.

[0007] As a result, the drive sleeve cannot rotate independently of the ratchet when the drive is removed, thus improving the user experience and speeding up the drive changing process (e.g., when changing direction or drive type).

[0008] In comparison to prior art drive assemblies, alignment of the drive sleeve and ratchet may be easier, for example, during removal and reinsertion of the drive.

[0009] The drive sleeve and the ratchet may include a plurality of pairs of cooperating features arranged to prevent relative rotation of the drive sleeve and the ratchet when the drive sleeve is seated on the ratchet.

[0010] The cooperating features of the drive sleeve and ratchet may include a keyway in the ratchet and a key in the drive sleeve, the key being arranged to mate with the keyway.

[0011] The ratchet and drive sleeve may each have a lip that, in use, extends parallel to the length of the shaft, the lip of the drive sleeve being arranged for sliding receipt within the lip of the ratchet. Co-operating features may be provided on the lip.

[0012] The cooperating features are oriented relative to the internal splines to align the internal splines of the ratchet with those of the drive sleeve when engaged.

[0013] The drive assembly may further include a retainer (or multiple retainers) arranged to hold the drive sleeve in place within the housing.

[0014] The drive assembly may further comprise a second drive sleeve arranged to seat on a side of the ratchet remote from the first drive sleeve. The second drive sleeve may also have internal splines that match internal splines of the ratchet. The ratchet may comprise a second lip on the side of the ratchet remote from the first lip, the second drive sleeve extending parallel to the length of the shaft in use, the lip of the second drive sleeve arranged to be slidingly received within the second lip of the ratchet. A cooperating feature may be provided on the lip.

[0015] The first and second drive sleeves may be identical.

[0016] In embodiments having multiple drive sleeves, the drive assembly may include one or more retainers positioned to hold each drive sleeve in place within the housing.

[0017] The drive may be a square drive.

[0018] According to a second aspect of the present invention there is provided a torque wrench comprising a drive assembly according to the first aspect.

[0019] The torque wrench may be a hydraulic drive torque wrench.

[0020] According to a third aspect of the present invention there is provided a kit of components for forming a torque wrench, the kit comprising: Housing; a ratchet arranged to be mounted to the housing and having an internal spline; a drive comprising a shaft arranged to be removably received within the housing, the shaft passing through the ratchet and having external splines arranged to mesh with the splines of the ratchet such that rotation of the ratchet rotates the shaft; and a drive sleeve positioned to seat on the ratchet within the housing and having internal splines that mate with the internal splines of the ratchet Equipped with.

[0021] The drive sleeve and the ratchet include cooperating features arranged to prevent relative rotation of the drive sleeve and the ratchet when the drive sleeve is seated on the ratchet.

[0022] The kit may include multiple interchangeable drives.

[0023] The kit may include multiple drive sleeves. In embodiments having two drive sleeves, one may seat on each side of the ratchet, and each may have internal splines that match the internal splines of the ratchet.

[0024] The ratchet, drive and drive sleeve of the kit of components may together form a drive assembly as described in relation to the first embodiment.

[0025] 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]

[0026] [Figure 1] FIG. 1 shows a perspective view of a square drive hydraulic wrench, showing the square drive in the context of the tool with the drive installed. [Diagram 2] FIG. 2 illustrates a perspective view of the square drive hydraulic wrench shown in FIG. 1 with the drive removed. [Diagram 3] FIG. 3 illustrates a cross-sectional perspective view of a portion of the square drive hydraulic wrench shown in FIGS. 1 and 2, focusing on the drive assembly. [Figure 4] FIG. 4 shows a perspective view of the drive sleeve and ratchet of the hydraulic wrench shown in the above figure. [Diagram 5] FIG. 5 shows a plan view of a square drive hydraulic wrench similar to that shown in FIG. 1 with the drive installed and line C indicated. [Figure 6] FIG. 6 shows a cross-sectional view of the square drive hydraulic wrench of FIG. 5 taken along line C. [Figure 7] FIG. 7 illustrates a perspective view of the ratchet and drive sleeve of the hydraulic wrench of FIG. 5, highlighting features A and B of the drive sleeve and ratchet, respectively. [Figure 8] FIG. 8 illustrates an enlarged perspective view of feature A of the drive sleeve shown in FIG. [Figure 9] FIG. 9 shows an enlarged perspective view of feature B of the ratchet shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Although embodiments of the present invention have been shown and described primarily with reference to square drives, it will be appreciated that different drives may be used in other embodiments, and the term "square drive" is therefore used only as an illustrative example and is not intended to be limiting.

[0028] FIG. 1 shows a tool 1, more specifically a square drive hydraulic wrench 1, according to an embodiment of the present invention.

[0029] The tool 1 comprises a housing 2 to which a drive assembly 10 is mounted. The tool further comprises a reaction arm 3 and a pivot assembly 4. The reaction arm 3 and pivot assembly 4 may be of any type known to those skilled in the art and / or one or both may be absent in other embodiments. For example, the pivot assembly 4 may be replaced with a different form of hose connector to allow the hydraulic tool 1 to be coupled to a pump (not shown), or an entirely different power source may be coupled for a non-hydraulic tool (e.g., a power tool).

[0030] The drive assembly 10 more specifically comprises a drive 11, which in the embodiment shown is a square drive 11. Different drives 11 may be used in other embodiments.

[0031] The drive assembly 10 also includes a ratchet 14 having external teeth or splines 14d arranged to mate with a mechanism (not shown) in the housing 2 of the tool 1 to rotate the ratchet 14 when power is applied to the tool 1. Any suitable mechanism known in the art may be used to rotate the ratchet.

[0032] In the embodiment being described, the drive assembly 10 is housed within a bore or passageway 2a that extends through the housing 2. In the embodiment shown, the passageway 2a is at least substantially cylindrical near the inlet and outlet and widens in an intermediate portion to accommodate the ratchet 14.

[0033] The drive assembly 10 comprises a pair of drive sleeves 13; the drive sleeves are arranged to be inserted into each of the ends of the passage 2a to support and position the drive 11. The drive sleeves 13 may also be referred to as bushings, as they provide a generally cylindrical lining for the opening and act as guides.

[0034] Each drive sleeve 13 is for aligning a ratchet 14, and more specifically, a splined axis of the ratchet, with a bore 2a in the housing 2. The drive sleeves 13 also provide a bearing surface to keep the housing 2 and drive 11 aligned. In the illustrated embodiment, each drive sleeve 13 is retained within the housing 2 by a retaining clip 12.

[0035] One or more retainers 12, e.g., retaining clips, are used to retain the drive sleeve 13 in the housing 2 during use. In the illustrated embodiment, the retaining clips 12 are arranged to retain the drive 11 in the housing 2 even when the drive 11 is removed from the housing. In FIG. 1, the retaining clips 12 are hidden, but they are visible in FIGS. 3 and 6. In particular, the upper retaining clips 12 are hidden by the square drive retainer 5 in the orientation shown in FIG. 1. The drive retainer 5 prevents the square drive 11 from slipping out of the tool 1. The illustrated design of the drive retainer 5 is provided by way of example only and is not intended to be limiting, and alternative components or features may be substituted in other implementations.

[0036] In other embodiments, only a single drive sleeve 13 may be used, or three or more drive sleeves 13 may be used. The drive sleeves 13 are substantially ring-like or cylindrical in shape. The outer surface of each drive sleeve 13 is disposed for a snug fit with the passageway 2a, and in the illustrated embodiment is smooth. The drive sleeves 13 are disposed to rotate within the passageway and slide in and out of the passageway with little or no resistance.

[0037] In the illustrated embodiment, the ratchet 14 and the drive sleeve 13 each have an at least substantially circular through opening; the openings are aligned and positioned to receive the drive 11 therein. The ratchet 14 and the drive sleeve 13 each have internal splines. In the illustrated embodiment, these internal splines 13a, 14a are oriented parallel to the length of the passage and perpendicular to the cross section of the circular through opening. In the illustrated embodiment, the internal splines 13a of the drive sleeve 13 match those of the ratchet 14a in both width and spacing. In an alternative embodiment, the drive sleeve 13 can have fewer internal splines 13a than the ratchet 14, however, these splines 13a are still positioned to align with the splines 14a of the ratchet 14 (some ratchet splines 14a may not be paired with drive sleeve splines 13a).

[0038] The drive 11 has an at least substantially cylindrical shaft 11b and a head 11c. The drive 11 is a square drive, so that the head 11c has an at least substantially square cross section in the embodiment shown. Heads of different shapes and / or sizes may be provided in other embodiments.

[0039] The shaft 11b is arranged to pass through the housing 2, more specifically in the passage 2a, in the order drive sleeve 13-ratchet 14-drive sleeve 13. The drive 11 has external splines 11a on the shaft 11b which are aligned with and arranged to mesh with the internal splines 13a, 14a of the drive sleeve 13 and ratchet 14 in use.

[0040] Rotation of the ratchet 14 when power is applied to the tool 1 therefore rotates the drive 11 through the interaction of the splines 11a, 14a. The drive sleeve 13 is arranged to rotate with the ratchet 14 and the drive 11.

[0041] The drive sleeve 13 helps form a bond between the housing 2 and the remainder of the drive assembly 10 .

[0042] In the illustrated embodiment, each drive sleeve 13 has a small spigot 13b, i.e., an edge of the drive sleeve 13 located adjacent the ratchet 14, shaped to enter the enlarged edge of the ratchet 14 to form a joint, as is known for pipes (the term "spigot" is used herein for brevity in its British English sense of an end of a pipe which enters an enlarged end of another pipe to form a joint, rather than its American English sense of a tap). The ratchets 14 have corresponding stepped openings or counterbores 14e on either side of the ratchet 14. For each of the drive sleeves 13, the spigot 13b is arranged such that in use it is located within the counterbore 14e on the corresponding side of the ratchet 14 when the drive sleeve 13 is inserted into the passage 2a. Although this feature is described above as a countersink 14e because of its shape, this term is not intended to limit this feature to being formed by drilling, and it will be appreciated that ratchet 14 may be manufactured in any suitable manner.

[0043] In particular, in the illustrated embodiment, the ratchet 14 comprises a central cog-like portion having external teeth and internal splines 14a, and circular rims 14b extending outwardly on either side of the cog-like portion. The rims 14b may also be referred to as lips 14b, and in the illustrated embodiment, the inner surface of the lip 14b provides a counterbore 14e. The internal splines 14a terminate short of the circular rim 14b. Due to the absence of at least the internal splines 14a, the rim 14b thus provides a wider opening than the cog-like portion of the ratchet 14. Correspondingly, one side of each drive sleeve 13 is stepped inwardly to provide a narrower rim or neck that functions as a spigot 13b. The necks 13b are sized and shaped to fit within the rims 14b of the ratchet 14.

[0044] Alternatively, the spigot and countersink arrangements 13b, 14e may be described as the ratchet 14 and drive sleeve 13 having lips 13b, 14b, respectively, that extend parallel to the passageway 2a / internal splines 13a, 14a, where the lips 13b, 14b are sized and shaped such that the lip 13b of the drive sleeve 13 is slidingly received within the lip 14b of the ratchet 14. In the embodiment described, the cooperating features are provided on the lips 13b, 14b.

[0045] The lips 13b, 14b include cooperating features 13c, 14c arranged to prevent relative rotation between the drive sleeve 13 and the ratchet 14 when the drive sleeve 13 is seated on the ratchet 14. The cooperating features interlock, thus coupling the drive sleeve 13 to the ratchet 14 for rotation therewith. In alternative embodiments, the drive sleeve 13 and the ratchet 14 may have different designs, optionally without spigots or countersinks, or the rim of the ratchet 14 may fit onto the drive sleeve 13 rather than vice versa, and / or the cooperating features 13c, 14c may be provided in different locations.

[0046] In the embodiment shown, the cooperating features of the ratchet 14 include two keyways or channels 14c that are arranged parallel to the length of the internal spline 14a and thus the passageway 2a and extend along the height of the rim 14b. The channels 14c are positioned opposite each other in the embodiment shown and are symmetrical so that the drive sleeve 13 can be fitted with the ratchet 14 in two different orientations. The cooperating features of the drive sleeve 13 include two keys or protrusions 13c that are positioned, sized and shaped to snugly fit into the channels 14c. The protrusions 13c are in the form of blocks that extend outwardly from the narrow rim 13b of the drive sleeve 13 along the height of the rim 13b. The lip / insertion portion 13b of the drive sleeve 13 can therefore slide into the countersink 14e on the rim 14b of the ratchet 14 only in two positions where the cooperating features 13c, 14c align and fit together.

[0047] The cooperating features 13 c , 14 c are positioned such that when the rim 13 b of the drive sleeve 13 is inserted into the ratchet 14 , the internal splines 13 a of the drive sleeve 13 are necessarily aligned with the internal splines 14 a of the ratchet 14 .

[0048] In alternative or additional embodiments, only a single key 13c and keyway 14c may be provided, or more than two pairs of keys and keyways may be provided. In some embodiments, more keyways 14c may be provided than keys 13c, such that one or more keyways 14c remain empty during use. In some embodiments, one or more keys may be located in keyways of the ratchet 14 and drive sleeve 13.

[0049] In the illustrated embodiment, the key 13c and keyway 14c have a constant width. In alternative or additional embodiments, the keyway 14c may be wider and / or the key 13c may be narrower toward the edges designed to mate with other cooperating features (i.e., the edges of the rim 14b away from the internal splines 14a of the ratchet 14 and the edges of the drive sleeve 13 closest to the ratchet 14). This shape may facilitate the initial engagement of the cooperating features 13c, 14c and guide these parts together into position. The shape of the cooperating features 13c, 14c may then guide the drive sleeve 13 in the correct alignment with the ratchet 14 as it is pushed further into the passage 2a. Similarly, as shown most clearly in Figures 7 and 8, the internal splines 13a of each drive sleeve 13, in the illustrated embodiment, are relatively shallow for most of the length of the drive sleeve 13, and extend radially only near the spigot 13b so as to accommodate the ratchet splines 14 when they meet. The shaped internal splines 13a of the drive sleeve 13 may help guide the drive 11 in the correct orientation as it is inserted into the drive sleeve 13. In alternative embodiments, the shape of the splines 13a may not change along the length of the drive sleeve 13. Alternative embodiments may have splines that extend axially a short distance, are located in the region of the spigot 13b, and do not extend further (in the radial extent).

[0050] In further alternative or additional embodiments, instead of or as well as different cooperating features 13c, 14c as described above may be provided. For example, the ratchet 14 may include one or more pins or other protrusions extending in a direction parallel to its internal splines 14a, and the drive sleeve 13 may include one or more openings or apertures extending in a direction parallel to its internal splines 13a and arranged to receive the pins or other protrusions of the ratchet 14, or vice versa. In such embodiments, the spigots and counterbores may not be provided and the cooperating features may extend from opposing faces of the drive sleeve 13 and ratchet 14 that are arranged to abut against one another in use.

[0051] In the embodiment shown, the cooperating features 13c, 14c are oriented parallel to the passageway 2a / parallel to the internal splines 13a, 14a so that the drive sleeve 13 can be inserted by simply sliding them into the passageway 2a and over the ratchet 14. In alternative embodiments, the cooperating features 13c, 14c may be oriented differently, for example formed with a thread or bayonet type arrangement such that relative rotation of the drive sleeve 13 and ratchet 14 is required to fully engage the cooperating features 13c, 14c.

[0052] In use, the drive 11 is inserted into the housing 2 via the first drive sleeve 13, then the ratchet 14, then the second drive sleeve 13. The drive 11 can then be removed and reinserted from the other side of the tool 1 if or when a change in drive direction is required, or the drive 11 can be removed and replaced with a different drive 11. Without the cooperating features 13c, 14c, the drive sleeve 13 would rotate freely within the passage 2a when the drive 11 was removed, resulting in misalignment between one or more of the drive sleeves 13 and the ratchet 14. Thus, the use of the cooperating features 13c, 14c avoids the need for the user to manually realign the internal splines 13a, 14a to reinsert the drive 11.

[0053] The cooperating features 13c, 14c are positioned such that the cooperating features 13c, 14c must be properly aligned in order for the drive sleeve 13 to be fully inserted into the housing 2. The cooperating features 13c, 14c are oriented relative to the internal splines 13c, 14c to ensure that the drive sleeve 13 and the ratchet 14 are properly aligned when the drive sleeve 13 is fully inserted (i.e., contact occurs between their opposing surfaces) so that the drive sleeve 13 seats on the ratchet 14. The cooperating features 13c, 14c also ensure that the drive sleeve 13 cannot rotate independently of the ratchet when the drive 11 is removed.

[0054] In the illustrated embodiment, the lip 14b of the ratchet 14 and the drive sleeve 13 are symmetrical and have identical cooperating features such that the two drive sleeves 13 are interchangeable. In other embodiments, the cooperating features on each side of the ratchet 14 may be different, such as each drive sleeve 13 being capable of mating with only one side of the ratchet 14. In embodiments where more than two drive sleeves 13 are provided, such as for a wider tool 1 having a longer passageway 2a, the additional drive sleeves 13 may be inserted into the passageway 2a and engage with the outer edge of the first drive sleeve 13. Additional cooperating features may be provided to allow drive sleeves 13 on the same side of the ratchet 14 to be intermeshed with each other.

[0055] Once fully inserted, the drive sleeve 13 can be secured in place using one or more retaining clips 12 and / or other retainers known in the art.

[0056] Tool 1 shown in Figures 1 and 2 may also include various other features standard in the art, such as a reaction pawl within tool 1 that provides an anti-backlash mechanism, and optionally a reaction pawl lever 7 shown in Figure 1 that may be used to disengage the reaction pawl from ratchet 14 if tool 1 becomes locked onto the object it is being used to apply torque to. It will be recognized that features common in the art and well known to those of ordinary skill in the art may be present as desired, although not described in detail herein.

Claims

1. 1. A torque wrench drive assembly comprising: a ratchet having an internal spline; a drive comprising a shaft arranged to be removably received within said ratchet, said shaft passing through said ratchet and having external splines arranged to mesh with said splines of said ratchet such that rotation of said ratchet rotates said shaft; and a drive sleeve positioned to seat on the ratchet and having internal splines that mate with the internal splines of the ratchet; Equipped with A drive assembly wherein the drive sleeve and ratchet include cooperating features positioned to prevent relative rotation of the drive sleeve and ratchet when the drive sleeve is seated on the ratchet.

2. 2. The drive assembly of claim 1, wherein the drive sleeve and ratchet include a plurality of pairs of cooperating features arranged to prevent relative rotation of the drive sleeve and ratchet when the drive sleeve is seated on the ratchet.

3. 3. The drive assembly of claim 1 or claim 2, wherein the cooperating features of the drive sleeve and ratchet comprise a keyway in the ratchet and a key in the drive sleeve, the key being arranged to mate with the keyway.

4. 3. A drive assembly as claimed in claim 1 or claim 2, wherein the ratchet and drive sleeve each have a lip that, in use, extends parallel to the length of the shaft, the lip of the drive sleeve arranged to be slidingly received within the lip of the ratchet, and the cooperating feature is provided on the lip.

5. 3. A drive assembly according to claim 1 or claim 2, wherein the cooperating features are oriented relative to the internal splines to align the internal splines of the ratchet with those of the drive sleeve when engaged.

6. 3. The drive assembly of claim 1, further comprising a second drive sleeve, the second drive sleeve being positioned to seat on a side of the ratchet remote from the first drive sleeve.

7. A drive assembly according to claim 1 or claim 2, further comprising one or more retainers arranged to hold the or each drive sleeve in place within the housing.

8. 3. A drive assembly according to claim 1 or claim 2, wherein the drive is a square drive.

9. A torque wrench having a drive assembly as described in claim 1 or claim 2.

10. 10. The torque wrench of claim 9, wherein the torque wrench is a hydraulic torque wrench.

11. 1. A kit of components forming a torque wrench, comprising: Housing; a ratchet arranged to be mounted to the housing and having an internal spline; a drive comprising a shaft arranged to be removably received within the housing, the shaft passing through the ratchet and having external splines arranged to mesh with the splines of the ratchet such that rotation of the ratchet rotates the shaft; and a drive sleeve positioned to seat on the ratchet within the housing and having internal splines that mate with the internal splines of the ratchet; Equipped with The drive sleeve and ratchet include cooperating features arranged to prevent relative rotation of the drive sleeve and ratchet when the drive sleeve is seated on the ratchet.

12. The kit of components of claim 11 , wherein the kit comprises a plurality of interchangeable drives.

13. 13. A kit of components according to claim 11 or claim 12, wherein the kit comprises a plurality of drive sleeves.

14. 13. A kit of components as claimed in claim 11 or claim 12, wherein the ratchet, drive and drive sleeve together form a drive assembly as claimed in claim 1 or claim 2.

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