tool

Abstract

An engagement member for a tool such as a hydraulic wrench (10), the engagement member (1) such as a ratchet connector engages with a workpiece and a powerhead (11), the engagement member (1) is arranged to translate motion generated by the powerhead (11) into motion of the workpiece, the engagement member (1) comprises a mount for the powerhead, the mount comprising a movable portion, the movable portion is movable from a first position in which the powerhead (11) is fixed relative to the engagement member (1) and a second position in which the powerhead (11) is movable relative to the engagement member (1), the movable portion comprises a pin (4) having a length and being slidable along its length in a bore (17) of the engagement member (1), and a friction lock, the friction lock comprising a compressible member (such as a compressible washer (3)) and a compression member (such as a threaded screw (2)) arranged to compress the compressible member, the compressible member is arranged such that it expands over at least one extent when compressed by the compression member, such that in a locked position of the friction lock, the compressible member expands to contact the pin (4) thereby limiting motion of the pin (4).

Description

TECHNICAL FIELD

[0001] The present invention relates to tools, in particular to engagement components of tools, for example, but not exclusively, hydraulic wrenches. BACKGROUND

[0002] Hydraulic wrenches are well known in the art. Atlas Copco, like other suppliers, offers an RTX hex drive hydraulic wrench which includes a detachable power head which can engage a ratchet connector which itself engages a workpiece (typically a hex nut or hex bolt head etc). The power head provides motion derived from hydraulic power, the ratchet connector converts this motion into rotation of the workpiece.

[0003] To change the power head / ratchet head combination, some form of detachable mounting can be used. Typically, this can comprise a fixed component (e.g. a fixed pin which works in a slot) and a detachable component (e.g. a detachable pin which works in a hole, removal of which allows the two components to be detached).

[0004] However, it can be troublesome to retain such detachable components, in particular pins. Pins can fall out, causing the power head and ratchet connector to separate, causing tool malfunction, and also presenting a dropped object hazard. SUMMARY

[0005] One suggestion used by our RTX hydraulic wrenches is to provide a circumferential groove on the pin and a spring loaded ball-brake in the hole. This will retain the pin. However, it is desirable to improve the safety of retaining the pin compared to these methods.

[0006] According to a first aspect of the present invention, we provide an engagement component of a tool, the engagement component being arranged to engage a workpiece and a power head, the engagement component being arranged to convert motion produced by the power head into motion of the workpiece, the engagement component comprising a mounting for the power head, the mounting comprising a moveable portion which is moveable from a first position in which the power head is fixed relative to the engagement component and a second position in which the power head is moveable relative to the engagement component.

[0007] The moveable portion comprises a pin having a length and being slidable along its length in a hole of the engagement component, and a friction lock comprising a compressible member and a compression member arranged to compress the compressible member, the compressible member being arranged such that it expands in at least one dimension when compressed by the compression member, such that in a locked position of the friction lock, the compressible member expands to contact the pin, thereby restricting movement of the pin.

[0008] Thus, this provides a pin that is reliably held in place by frictional engagement of a compressible member that is pushed into place by the action of the user. Thus, there is less chance of the pin falling out of the engagement member unintentionally compared to relying on a spring biased ball bearing press only, for example, in a groove in the pin. The pin can be sized and shaped to pass through a portion of the power head.

[0009] The pin can have a uniform cross-section over a portion of its length, which is typically a majority of the length. The cross-section can be non-circular.

[0010] Typically, the cross-section will have a circumference and comprise a first shape on a first portion of the circumference and a second shape on a second portion of the circumference. Typically, the first and the second shape will be non-concentric circular arcs, the centre of the circular arc forming the second shape being outside the cross-section. Thus, this describes a generally cylindrical pin with a crescent shaped key taken out and which is easy to machine.

[0011] The portion of the length can not extend to a retained end of the pin, which is captured in the hole by the compressible member, if not also the compression member. The retained end can have a cross-section of the first shape. The compressible member can be arranged to engage the pin on the second portion of the circumference. The compressible member can have a circumference that is complementary to the second shape; thus, the compressible member can be circular and can have a variable radius depending on the degree of compression applied to the compressible member, wherein in the locked position the compressible member is typically frictionally engaged with the pin on the second shape.

[0012] Thus, the compressible member can comprise a compressible washer and the compression member can comprise a bolt and a head, the head providing a flange that bears on the compressible washer. The bolt is mounted in a threaded hole of the engagement member; typically, the threaded hole is parallel to the hole, which is also easy to manufacture. The head can be used to secure the retained end in the hole.

[0013] The compressible washer can be formed of an elastomeric material, in particular an elastomer such as polyurethane.

[0014] The pin can comprise a circumferential groove around its circumference, which can be engaged by a biasing member in the power head.

[0015] This provides further redundancy in retaining the pin and provides a positive confirmation to the user that the pin is in place when the user can feel the biased member enter the groove.

[0016] In addition to the moveable portion, the mount of the engagement member can comprise a fixed portion that provides a fixed position for the power head. Typically, the fixed portion can comprise a slot for a pin of the power head.

[0017] Typically, the workpiece will include a hex bolt head or a hex nut. Therefore, the mating components may include a hex actuator for driving the hex bolt or nut. The hex actuator may be a ratchet hex actuator, as it can only rotate in a single direction, which can be optionally selected by the user.

[0018] The power head can be a hydraulic power head.

[0019] According to a second aspect of the invention, we provide a tool comprising a coupling member and a power head, the power head being coupled to the mounting member such that the power head can provide power to the coupling member to move a workpiece.

[0020] The tool can be, for example, a hydraulic wrench; therefore, the power head can be a hydraulic power head.

[0021] The power head may include a hole for the pin. The power head may also include a biasing member and a biased member that tends to be biased into engagement with a groove in the pin through the wall of the hole in the power head in a first position of the movable portion. Typically, the biased member will be held captive in the power head, usually by working in another hole in the power head having a slit into the hole in which the pin works, the diameter of the slit being smaller than the diameter of the biased member. Typically, the biased member will include a spherical member, such as a ball bearing, and the biasing member will include a spring in the other hole.

[0022] According to a third aspect of the invention, a component kit for forming a tool is provided, the kit comprising at least three components selected from the group consisting of, at least one of the following components:

[0023] At least one engaging member according to the first aspect of the invention; and

[0024] At least one power head that can engage with the mounting portion of each engaging component.

[0025] Therefore, this provides interchangeable systems of power heads and engagement components that can be used for different purposes (e.g., workpieces of different sizes, different force or power requirements). Attached Figure Description

[0026] Embodiments of the invention described with reference to the accompanying drawings will now be described by way of example only, wherein:

[0027] Figure 1 A perspective view of a ratchet connector for a hydraulic wrench according to an embodiment of the present invention is shown;

[0028] Figure 2 Showing Figure 1 Different perspective views of the ratchet connector;

[0029] Figure 3 shows a partial exploded perspective view of the ratchet connector of Figure 1

[0030] Figure 4 shows a perspective view of the ratchet connector of Figure 1 in combination with a power head to form a hydraulic wrench;

[0031] Figure 5 shows a perspective view of the hydraulic wrench formed from the components of Figure 4

[0032] Figure 6 shows a partial cutaway perspective view of the hydraulic wrench of Figure 5

[0033] Figure 7 shows a partial cross-section of the hydraulic wrench of Figure 5 DETAILED DESCRIPTION

[0034] The accompanying drawings show a hydraulic wrench 10 formed from a ratchet connector 1 (otherwise described above as an engagement component) detachably connected to a power head 11. The power head utilizes a hydraulic power source to produce movement of a piston rod end 12; this acts on the ratchet connector 1 and is used to rotate a hexagonal driver 13 which can rotate hexagonal workpieces such as hexagonal bolt heads or nuts.

[0035] In order to mount the power head 11 on the ratchet connector 1 (both of which are attachable to other such components where different pairings of power head and ratchet connector are possible), a mounting is provided. This comprises a fixed slot 14 in the ratchet connector 1 which receives a fixed pin 15 on the power head 11, and a pin 4 working in a first hole 17 in the ratchet connector 1 and received in a hole 16 on the power head 11, the pin 4 being slidable.

[0036] In this way, the power head 11 and ratchet connector 1 are fixed together by the fixed pin 15 in the slot 14 and the pin 4 received in the hole 16. In order to detach the two components, the pin 4 is withdrawn from the hole 16 in the power head 11, and the power head can then be removed from the ratchet connector 1.

[0037] It is desirable to retain the pin 4 in some way to ensure that it does not accidentally withdraw from the hole 16, and further that it does not fall completely out of the ratchet connector 1. To this end, a friction lock is provided. This comprises a threaded screw 2 with a head 5 of larger diameter and a compressible washer 3. The threaded screw 2 works in a second threaded hole 18 in the ratchet connector 1 parallel to the first hole 17 (thus facilitating machining).

[0038] ​​​​The cross-section of the pin 4 is circular, but has a partial circular cut-out 19 which is substantially coaxial with the second hole 18 (except for an end 21 explained below).

[0039] Frictional locking acts on the cut-out 19. The compressible washer 3 is made of a material which expands, particularly radially outwards from the second hole 18, when compressed by the threaded screw 2, particularly the flange formed by the head 5 of the screw. This means that if the user screws the threaded screw 2 into the second hole to the maximum, the compressible washer 3 will expand as far outwards as possible, engaging with the pin 4 and preventing or at least limiting its withdrawal. If required, the user can unscrew the threaded screw 2 so that the compression of the compressible washer 3 is reduced and its radial extent is reduced. The pin 4 can then be removed freely to allow removal of the power head 11 from the ratchet connector 1. However, it is envisaged that the frictional locking will provide a frictional force so that the user can remove the pin against the frictional force created by the frictional locking, but will prevent inadvertent removal or disengagement of the pin.

[0040] As can be seen in the Figure 7 cut-out 19 does not extend the entire length of the pin 4 and is not present at the end 21 which is retained in the ratchet connector 1, at which point the pin 4 is a full circle. Thus, with the screw in place, the pin 4 cannot pass through the threaded screw 2 and the compressible washer 3. This can prevent the pin 4 from falling out accidentally.

[0041] The power head 11 is also provided with a spring-loaded ball 20 which works through a slot in the hole 16 to be received within the groove 6 in the pin. This can help to retain the pin 4 in the power head 11 and the ratchet connector 1 and can provide positive feedback to the user that the pin has been inserted in the correct position, as the ball 20 can be felt to engage the groove 6. However, this is merely a back-up to the frictional locking.

[0042] In this way, with this frictional locking, the pin 4 can be prevented or limited from slipping out in use; as the pin cannot (or is less likely to) disengage from the power head 11, tool reliability is increased. The pin 4 is less likely to fall out and less likely to present a falling hazard than, for example, a spring-loaded ball of the prior art. Having the first and second holes parallel means that they are easy to machine.

Claims

1. A tool engaging component arranged to engage a workpiece and a power head, the engaging component arranged to convert motion generated by the power head to motion of the workpiece, the engaging component comprising a mount for the power head, the mount comprising a movable portion movable from a first position in which the power head is fixed relative to the engaging component and a second position in which the power head is movable relative to the engaging component: the movable portion comprising a pin having a length and slidable along its length in a bore of the engaging component, and a friction lock comprising a compressible member and a compression member arranged to compress the compressible member, the compressible member arranged such that it expands in at least one degree of extension when compressed by the compression member, such that in a locked position of the friction lock the compressible member expands to contact the pin, thereby limiting movement of the pin.

2. The engaging component of claim 1, wherein the pin has a uniform non-circular cross section over a portion of the length thereof.

3. The engaging component of claim 2, wherein the cross section has a circumference and comprises a first shape over a first portion of the circumference and a second shape over a second portion of the circumference, the first and second shapes being non-concentric circular arcs, the center of the arc forming the second shape being outside the cross section.

4. The engaging component of claim 3, wherein the compressible member is arranged to engage the pin over the second portion of the circumference.

5. The engaging component of claim 4, wherein the compressible member has an outer circumference complementary to the second shape; the compressible member is circular and has a variable radius dependent on the degree of compression applied to the compressible member by the compression member, wherein in the locked position the compressible member generally frictionally engages the pin over the second shape.

6. The engaging component of claim 5, wherein the compressible member comprises a compressible washer and the compression member comprises a bolt and a head, the head providing a flange bearing on the compressible washer.

7. The engaging component of claim 6, wherein the bolt is mounted in a threaded hole in the engaging component, wherein the threaded hole is parallel to the bore.

8. The engaging component of any one of claims 2 to 7, wherein the portion of the length does not extend to a retained end of the pin, the retained end being captured in the bore at least by the compressible member.

9. The engaging component of claim 8, wherein the retained end is captured in the bore at least by the compressible member and the compression member.

10. The engaging component of claim 8, wherein the retained end has a cross section of the first shape.

11. The engaging component of any one of claims 1 to 7, wherein the mount of the engaging component comprises a fixed portion providing a fixed position for the power head.

12. A tool comprising the engagement component of any one of claims 1 to 11, and a power head engaged on the mounting such that the power head can power the engagement component to move the workpiece.

13. The tool of claim 12, wherein the pin comprises a circumferential groove around its circumference, and the power head comprises a bore for the pin, a biasing member and a biased member, the biasing member tending to bias the biased member into engagement with the groove through a wall of the bore in the power head in the first position of the movable portion.

14. The tool of claim 13, wherein the biased member is captured in the power head by working in another bore in the power head, the other bore having a slit into the bore in which the pin works, wherein the diameter of the slit is less than the diameter of the biased member.

15. The tool of claim 12, the tool being a hydraulic wrench.

16. A kit of parts for forming a tool, the kit comprising at least three components selected from the group of: at least one engagement component of any one of claims 1 to 11; and at least one power head engageable with the mounting portion of each engagement component.

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