GB2517245A

GB2517245A - Improved torque wrench

Info

Publication number: GB2517245A
Application number: GB1409022.9A
Authority: GB
Inventors: Stephen Quicke
Original assignee: Hire Torque Ltd
Current assignee: Hire Torque Ltd
Priority date: 2013-05-21
Filing date: 2014-05-21
Publication date: 2015-02-18
Also published as: GB201409022D0; GB201309131D0

Abstract

A torque wrench comprises a power head 10 and a ratchet link 1. The power head comprises an actuator 11 mounting a rod end 12, and the ratchet link includes a drive plate 4, the drive plate mounting a drive pin 4f. The rod end is releasably attachable to the drive pin, and the drive plate includes a pair of spaced apart walls 4a, a portion of the rod end being receivable in the space between the walls. Each of the walls include a slot 4c, the drive pin being mounted in the slots, each mounting a biasing means 4e configured to bias the pin. The pin may float in the slots against the biasing means, which may be a coil spring or a compression spring. The biasing means may be mounted in a recess 4g extending from the slot into the wall. In at least one of the walls, a side face may have a recess from which the slot extends, there may also be a plate (figure.1 4i) configured to sit in the recess which may lie in the same plane as the drive plate wall. The pair of walls may have a curved rod engagement face 4h.

Description

Improved Torque Wrench

Field of the Invention

The present invention relates to n)rque wrenches and in particular to a type of U)rc1ue wrench comprismg what is known as ratchet link and a power head.

Background of the Invention

Powered torque wrenches are used widely, particularly in the oil and gas industries, Thes torque wrenches are typically powered hydraulically and comprise a ratchet link and a power head, the ratchet link and power head being separable.

ihe general configuration of powered torque wrenches is well established, The main issues around powered torque wrenches at present lie in ease of use, reliability and ease of maintenance.

In particular, the point of connection of the ratchet link and the power head is subject to great forces, ibis part of the equipment must also provide for the attachment and detachment of the two components.

[he powered torque wrench typically includes a linear actuator, if the actuator is subject to forces moving it off its linear direction of travel the actuator will be subject to significant wear.

it would he desirable to provide a powered torque wrench which suffers less from the above-mentioned problems.

Summary of the Invention

According to the invention there is provided a torque wrench as specified in Claim 1. a

According to another aspect of the invention, there is provided a torque wrench as specified in Claim ii According to another aspect of the invention there is provided a ratchet link as specified in Claim 12.

The invention is particularly suited to hydraulic torque wrenches, although other power sources may be utilised, such as pneumatic or electrical power.

Preferred features of the invention are set out in the claims dependent on Claims 1, U and 12, die

description and thc drawings.

Brief Description of the Drawings

in the Drawings, which illustrate a preferred embodiment of a fluid powered torque wrench according to the invention: Figure 1 is a schematic representation of a torque wrench according to the invention; Figure 2 is a cross-sectional side view of the torque wrench illustrated in Figure 1; Figure 2a is a detailed schematic representation of die rod end of the power head of the torque wrench illustrated iii Figures 1 and 2; Figure 3 is a detailed schematic representation of the torque wrench shown in Figures 1 and 2 with the actuator Filly extended; Figure 4 is a schematic representation of a component of the torque wrench illustrated in Figures 1 to 3 with the actuator Fully retracted; and Figure 5 is a cross-sectional side view of the assembled torque wrench.

Detailed Description of the Preferred Embodiments

Figures 1 and 2 illustrate a hydraulic torque wrench which comprises a ratchet link 1 and a power head 10, the ratchet link 1 comprises side plates 2 separated by a spacer 7. A drive plate 4 is mounted in the space between the side plates 2. The drive plate 4 is mounted for rotation relative to the side plates 2 and is secured in position by a hex ratchetS, which includes ratchet teeth 5' and flanges 5" on each side thereof Each flange 5" sirs in a hole o I substantially corresponding diameter in a side plate 2. With the ratchet link 1 assembled, the drive plate 4 is constrained against movement other than about the centre axis of the hex ratchet 5.

A single drive pawl 6, having teeth 6" is mounted in a housing S in the drive plate 4. A spring 9 sits between the drive pawl 6 and an ad jacent wall of the housing Sand is located in aligned bores in each of the said components.

The drive plate 4 inellides a biflireated end portion providing walls 4a and all opening 11). The opening 4b receives the rod end 12 of the power head tO.

Referring now to Figures 1 to 2a, the rod end 12 includes a stub-shafr 12a that fits into bore hi die end of a piston 1 lb of an actuator 11. the rod end 12 provides the means by which the power head 10 may releasably attach to the ratchet link i. The rod end 12 includes all end face which includes a curved nose portion 12b and a slanting wall, The slanting wall ternainates at the opening of a slot 12d. The rod end 12 fhrther includes horizontally extending walls 12e, the lower end of each wall 12e presenting a chamfrrred edge 12 the slot l2dt engages a drive pin 4 which is niountect in the drive plate 4. the configuration of the moutlng of tIle drive pin 4f is particularly advantageous, m2dcing servIcing of the equipment straightforward.

[he drive plate 4 includes a slot 4c in each of the walls 4a. the slots 4c are elongate and radiussed at their opposing ends. Further the slot 4c in one of the walls 4a is aligned with the slot 4c in the other of the walls 4a. Each of the walls 4a includes a bore 4g which exnds from the top of the wall 4a into the body of the drive plate 4 through the slot 4c, as best seen in Figure 2,A spring 4e is seated in each of the bores 4g, that heingin the part of the bore 4g in the body of the drive plate 4. Ihe pin 4fis situated in the slot, with each of the springs 4e biasing the pin 4f into the uppermost position shown in Figure 2.

Figure 1 shows that the outer faces of walls 4a include a recess 4d which in this case is circular, The pulpose of the recess is to provide for containment of the pin 4f. The pin 4fis not Axed in position, rather it floats on the springs 4e. A circular plate 4i is provided fbr the recess 4d of each of the walls 4a, With the plate 4i in place, a tlush surface is provided.

With the ratchet link 10 asscmhled, the pin 4f is held in place hy virtue of the attachment of side plates 2 to each other, each side wall of the drive plate 4heing in sliding contact with the iiuier surface of one of the side plates 2, it will be appreciated by one skilled in the art that the drive pin 4f and its associated components are very simple to assemble and disassemble, In fact, once the side plates 2 have been released from one another, no tools are required.

To assemhle the power head 10 to the ratchet link 1 the pin 15 of the power head is engaged with slots 2a of the side plates 2, the power head 10 then being h)wered into the ratchet link so that a pin 16 may be passed through aligned holes in the 2b in the side walls 2 and 16 in the power drive. A pin 17 is passed through the aligned holes to secure the power head 10 to the ratchet link 1.

The rod end 12 is self-locating on the pin 4f. Hydraulic fluid is introduced into the cylinder 1 la of hydraulic actuator 11, thereby advancing the piston lib in the direction of the drive plate 4. The angled face 12c of the rod end 12 engages the pin 4 the angled kice 12c engages with the curved surface of the pin 4 Since the piston 1 lb and hence the tact end 12 wInch is attached ta the pistan llb ate canstrainect against movement other than along the axis of the piston and cylinder ilL, ii a-The rot] end 12 therefore causes the pin 4fta suave ctawnward in the slats 4c against die farce af the springs 4e-When the pin reaches the battam af the angled face 12c, as the tad end 12 is advanced further, the pin 4f becames alired with the slat 12d. l'he springs 4e Farce the pin 4finta the slat 12d.

The distance between the slot 1 2d and the face o fwalls I 2e is snch that with the pin 4f engaged in the slot 4c, when the piston lIb is advancing, die drive plate 4 is driven by engagenient of the walls 12e with the curved surfaces 4h of the walls 4h afthe drive plate 4. As can he seen from Figure 3 in particular, the teeth 6' of the drive pawl 6 engage with the teeth 5' of the hex ratchet 5, and hence advancing the piston 1 lb causes the drive plate 4 to ratate and the hex ratchet ta ratate with the ctrive plate 4, Titli the piston llb fully advanced, the drive plate is positioned as shown in Figure 4. As will be appreciated by one skilled in the art, when the piston ilL is retracted, the drive plate 4 is caused to rotate iii the anti-clockwise direction. The relative angles of the engaging surfaces of the ted 5' and 6' cause the drive pawl 6 to be lifted into die housing 8 off the teeth 5' of die hex ratchet 5, against the force of spring 9. In this direction of travel, the force exerted by the actuator 11 on the drive plate 4 is transmitted via the pin 4f.

However, the force is small, being the force reuiretl to cause the teeth 6' of drive pawl 6 to ride up over the teeth 5' of the hex tatchet 5. Ilence, the respective dimensions of slot 4c and pin 4f allow a small amount of play therehetween. This ensures that when driving the drive plate 4 in the clockwise direction, load is borne by the walls 12e not the pin 4f Another aspect of the invention lies in the configuration of die walls 4a of the drive plate 4, and in particular to the shape of the face 4h of each wall 4a facing the wall I 2e of the rod end 12 and its relationship with the piston 1 lb. The face 4h is curvet] having a radius of curvature R. The centre of the rathius of curvature lies on the centre axis x-x of the piston llb. this configuration of the cuted face 4h and the alignment of the centre of the radius of curvature R of the face 4h with the centre axis x-x of the piston 1 tb ensures that the piston llb may travel along a straight line between the two extremes of travel of piston 1 lb without being subjected to substantial sideways forces.

in the present example, the radius of curvature of the face 41i is 15 tutu, however, as one skilled in the art wiii appreciate, other radii may be selected depending on the dimensions of other components of the wrench.

Claims

Claims 1. A torque wrench comprising a power head and a ratchet link, the power head comprising u1 actuator mounting a rod end, and the ratchet link including a drive plate, the drive plate mounting a drive pin and wherein the rod end is releasablv attachable to the dnve pin, characterised in that the the drive plate includes a pair of spaced apart walls, a portion of the rod end being receivable in the space between the pair ofwalls, and each] of the pair of spaced apart walls including a slot, the drive pin being mounted in the slots, each slot mounting a biasing means configured to bias the drive pin towards one end of the slot.
2, A torque wrench according to Claim 1, wherein the drive pin floats in the slots against the biasing means.
3. A torque wrench according to Claim 1 or 2, wherein each wall includes a recess extending from the slot into said wall, and wherein the biasing Illeans is mounted in the recess.
4. A torque wrench according to Claim 3, wherein each wall includes an opening extending into the slot and digned with the recess.
5. A torque wrench according to any preceding claim, wherein the biasing means is a coil spring.
6. A torque wrench according to any preceding claim, wherein the biasing means is a compression spring.
7. A torque wrench according to any preceding claim, wherein a side face of at least one of the pair of spaced apart walls includes a recess, wherein the slot extends from the recess.
8. A torque wrench according to Claim 7, wherein the side face S all outer side face,
9. A torque wrench according to Claim 7 or 8, further comprising a plate configured to sit in the recess.
10. A torque wrench according to Claim c, wherein the plate is configured such that its outer free lies in the same plane as the outer face of the wall of the drive pltte.
11. A torque wrench coniprising a power head and a ratchet llnk, the power head comprising an actuator including a piston, the piston mounting a rod end, and the ratchet link including a drive plate, die drive plate mounting a drive pin and wherein the rod end is releasabely attachable to the dnve pin, characterised in that the the drive plate includes a pair of spaced apart walls, a portion of the rod end being receivable in the space between the pair of walls, wherein each of the pair of walls has a rod end engagement face and wherein the rod end engagement face is curved, and wherein the centre ofradhis GECUrVature of the curved engagment face lies on the axis of travel of tile piston of the actuator.
12. A ratchet link of a torcjue wrench, the ratchet Hnk including a drive plate, the drive plate mounting a drive pth for releasable attachment to a rod end of a power head, characterised in that the the drive plate includes a pair of spaced apart walls for recei\rhg the rod end, and each of the pair of spaced apart walls including a slot, the drive pni being mounted in the slots, each slot mounting a biasing means configured to bias the drive pin towards one end of the slot.
13. A ratchet link according to Claim 12, wherein the drive ph floats in the slots agahst the biasing iyleafls.
14. A torque wrench according to Claim 13, whein each wall includes a recess extendhg from the slot into said wall, and wherein the biasing means is mounted in the recess.
15. A torque wrench according to Claim 14, whettin each vall includes an openilig cxrending into the slot and aligned with the recess.
16. A urque wrench according to any of Claims 13 to 15, wherein the biasing means is a coil spring.
17. A torque wrench according to any of Claims 13 to 16, wherein the biasing means is a compression spring.
18. A torque wrench according to any of Claims 13 to 17, whcrein a side face of at least one of the pair afspaced apart walls includes a recess, wherein the slot extends from the recess.
19, A torque wrench according to Claim 18, whein the side face is an outer side face.
20. A torque wrench according to Claim 18 or 19, brther comprising a plate configured to sit in the recess.

21, A torque wrench according to Claim 20, wIiein the plate is configured such that ts outer face lies in the same plane as the outer face of the wall of the drive plate.