GB2513316A

GB2513316A - Wedge mechanism

Info

Publication number: GB2513316A
Application number: GB1307207.9A
Authority: GB
Inventors: Robert Stephen
Original assignee: Equalizer International Ltd
Current assignee: Equalizer International Ltd
Priority date: 2013-04-22
Filing date: 2013-04-22
Publication date: 2014-10-29
Anticipated expiration: 2033-04-22
Also published as: GB2513316B; WO2014174263A1; GB201307207D0

Abstract

A wedge mechanism for a separating tool is disclosed. The wedge 10 has a body with an axis extending between a trailing end and a leading end, and the body 10 tapers from the trailing end to the leading end. The wedge mechanism also comprises at least one plate 30 that is connected to the wedge 10 such that, as the wedge moves parallel to the axis, the plate 30 is moved radially away from the axis. The leading end comprises a leading edge insert 20 adapted to be removed from the body and replaced. A method of manufacturing is also disclosed, as is a method of using a separation tool. A wedge for a separating tool is also disclosed, the wedge having a body which tapers from a trailing end to a leading end. The leading end comprises a leading edge insert adapted to be removed from the body and replaced.

Description

Wedge mechanism The present invention relates to a wedge mechanism for a separating tool, typically S comprising a lifting or separating tool incorporating a wedge that moves axially in the tool to lift a heavy item, or to separate two items that are forced together.

Examples of the invention are typically useful in hydraulic or mechanical tools, and are typically useful in tools that use high operating loads, to lift heavy objects, or to apply high forces to separate items that are forced together at high loads, e.g. pipeline flanges.

Lifting and separating tools typically have a wedge mechanism that drives a wedge axiafly in a body of the tool, typically between two plates or jaws disposed on opposing sides of the wedge. As the wedge is driven along an axis between the plates, the plates separate to apply a lifting or separating force to an object The invention provides a wedge for a separating tool) the wedge having a body with an axis extending between a trailing end and a leading end, and wherein the body tapers from the trailing end to the leading end, wherein the leading end comprises a leading edge insert adapted to be removed from the body and replaced.

According to the invention there is also provided a wedge mechanism for a separating tool, comprising: a wedge and a body which tapers from a trailing end to a leading end; and at least one plate, the wedge having an axis, and the plate and wedge being connected such that as the wedge moves parallel to the axis, the plate is moved radially away from the axis, and wherein the leading end comprises a leading edge insert adapted to be removed from the body and replaced.

The invention also provides a method of making a separating tool) the separating tool having a wedge mechanism comprising a wedge having an axis and a body and at least one plate) the method comprising connecting the plate to the wedge such that as the wedge moves parallel to the axis, the plate is moved radially away from the axis) and providing the leading end of the body of the wedge with a leading edge insert adapted to be removed from the body and replaced, and wherein the method includes attaching the leading edge insert on the body by means of a releasable fixing.

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The invention also provides a method separating two objects, comprising providing a wedge having an axis and a body and providing at least one plate, connecting the plate to the wedge such that as the wedge moves parallel to the axis, the plate is moved radially away from the axis, and providing the leading end of the body of the wedge with a leading edge insert adapted to be removed from the body and repkced, and wherein the method includes inserting the leading edge of the wedge between the two objects, with the plate disposed between the wedge and one of the objects, driving the wedge axially to drive the plate parallel to the axis, thereby driving the plate away from the axis of the body and separating the objects, and wherein the method includes attaching the eading edge insert on the body by means of a r&easable fixing.

Typically as the wedge moves parallel to the axis, the direction of movement of the plate in relation to the wedge can have a perpendicuhr component and a paralle' component in relation to the axis. In certain examples of the invention, the plate is moved in a direction perpendicular to the axis.

By "separating" we include lifting, separating, and other similar acts.

Typically the body of the wedge is cast, typically from metal. The leading edge insert can be cast but is typically formed by a different method than the body of the wedge, for example, by milling or forging from metal. Optionally the leading edge insert can be formed from rolled steel and can be machined, e.g milled into a shape to form a part of the leading edge of the wedge body, or optionally forged. Typically the leading edge insert is harder than the body. Typically the leading edge insert comprises a harder material than the material of the body, or is formed from the same material, but treated to make the leading edge insert harder than the body.

Typically the leading edge insert is adapted to fit into a recess in the body of the wedge, and typically is configured to continue the tapered surfaces of the wedge body. Typically the recess is disposed at the leading end of the body. Typically the recess and the insert have complimentary shapes so that the overall taper of the wedge body is maintained across the recess by the insert, without deviation of the outer surface of the body over the recess, when the insert is in place.

Typically the insert is retained in the recess, typically by a fixing such as a bolt or screw, which can typically be removed to permit removal and replacement of the insert in the recess. Typically the insert is removed and replaced when it shows signs of wear.

Typically the recess is formed in the leading edge of the body of the wedge.

Typically the insert extends in an axial direction beyond the recess.

Typically insert comprises a plate. Typically the insert and the recess have generally flat surfaces, optionally with a generally rectangular shape, at least at the trailing end of the insert. Typically the insert has a leading edge that is tapered at the same taper as the body, and which typically extends from the recess, at the leading end.

Typically the recess and the insert have flat surfaces, typically rectilinear surfaces, typically with at least two rectangular faces. Typically at least one face of the recess is disposed axially behind the insert, to buttress the insert against axial movement in the recess. Typically that face is flat, and in particular examples could be rectangular. The buttressing face does not need to be perpendicular to the axis, or to the face of the body, but merely needs to resist axial movement of the insert in the recess.

Typically the leading edge insert forms the leading edge of the wedge body.

Typically the plate slides over the outer surface of the leading edge insert Typically the inner surface of the leading edge insert is pressed into the recess. Typically the inner and outer surfaces of the leading edge insert meet at a tip.

S Typically the or each plate is retained on the body by a retainer arm, or by a respective retainer arm in the case of more than one plate. Typically the retainer arm extends radially away from the axis of the body, and typically has a leading face and a trailing face. Typically the trailing face and/or the leading face can optionally be canted at an angle toward the leading end of the wedge with respect to the axis, but typically at least one of the trailing and leading faces (or both of them) is perpendicular to the face of the body on which the plate is engaged. Optionally the leading face of the arm is perpendicular to the axis. Optionally the leading and trailing faces of the arm can be parallel but this is not necessary and in some examples of the invention the leading and trailing faces are typically not parallel.

Typically the plate has an aperture that receives the radial extension of the arm, and typically the plate slides along the trailing face of the arm, at the angle defined by the trailing face of the arm.

The various aspects of the present invention can be practiced alone or in combination with one or more of the other aspects, as will be appreciated by those skilled in the relevant arts. The various aspects of the invention can optionally be provided in combination with one or more of the optional features of the other aspects of the invention. Also, optional features described in relation to one example can typically be combined alone or together with other features in different examples of the invention.

Various examples and aspects of the invention will now be described in detail with reference to the accompanying figures. Still other aspects, features, and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrates a number of exemplary aspects and implementations. The invention is also capable of other and different examples and aspects, and its several details can be modified in various respects, all without

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departing from the spirit and scope of the present invention. Accordingly) the drawings and descriptions are to be regarded as illustrative in nature) and not as restrictive. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope.

S Language such as "including," "comprising" "having," "containing," or "involving," and variations thereof; is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives) components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or to "containing" for applicable legal purposes.

Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention.

In this disclosure, whenever a composition, an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting essentially of', "consisting", "selected from the group of consisting of", "including", or "is" preceding the recitation of the composition, element or group of elements and vice versa.

All numerical values in this disclosure are understood as being modified by "about".

All singular forms of elements, or any other components described herein are understood to include plural forms thereof and vice versa. References to positional descriptions such as "upper" and "lower", and directions such as "up", "down" etc in relation to the invention are to be interpreted by a skilled reader in the context of the examples described and are not to be interpreted as limiting the invention to the literal interpretation of the term, but instead should be as understood by the skilled addressee.

In the accompanying drawings, Fig 1 is a side view of a wedge body for use in a wedge mechanism; Fig 2 is a plan view from beneath the fig 1 body; Fig 3 is a perspective view of the fig 1 body; Fig 4 is an exploded perspective view similar to fig 3; FigS is a side view of a separating tool incorporating the wedge body of fig 1, in which the piston is retracted; Fig 6 is a side sectional view of the fig S tool, in which the piston is retracted; Figs 7 and Bare side and section views similar to figs 5 and 6, but with the piston extended; Figs 9 and 10 are plan and section views from above of the tool of figS, with the piston retracted; Figs 11 and 12 are plan and sectional views similar to figs 9 and 10, with the piston extended; Figs 13 and 14 are perspective views of the tool with the piston retracted and extended respectively; Figs 15 and 16 are partial perspective views of the tool shown in fig S with certain components removed for clarity; and Fig 17 shows an exploded view of the tool shown in Fig S. Referring now to the drawings a wedge mechanism comprises a wedge having a body 10 with upper and lower faces 11, 12, which taper from a trailing end to a leading end. At the leading end the faces 11, 12 converge towards a tip, at which is located a leading edge insert 20 in the form of a generally flat plate, which is secured in a recess 15 on the body 10 of the wedge. The insert 20 has a flat outer surface 21 and a parallel flat inner surface 22, and generally flat sides, and typically all of the surfaces are generally rectilinear. Three of the flat sides of the insert 20 are typically perpendicular to the inner and outer surfaces, and one side is chamfered as will be discussed in more detail below.

The depth, width (and optionally the length) of the recess 15 typically matches the corresponding depth and width of the side walls of the insert 20. Thus when the insert 20 is located in the recess 15, the flat outer face 21 of the insert 20 is typically continuous with the flat upper face 11 of the body 10, so that the insert effectively S continues the flat upper surface 11 un-interrupted across the recess. Typically the leading-edge 201 of the insert 20 is chamfered to match the taper of at least one of the upper and lower surfaces ti, 12 of the body 10, and typically the leading-edge 20! of the insert 20 extends from the body to form the apex of the wedge, protruding out of the recess 15,so that when the insert 20 is secured in place in the recess 15 on the body 10, the leading-edge of the wedge is formed entirely by the insert 20, which typically extends in an axial direction out of the leading end of the body, by about 1 to 3 cm beyond the axial limits of the recess, as best seen in fig 1.

The outer face 21 of the insert 20 is flat all the way to the leading edge 201. The opposite lower face of the plate which engages the outer surface of the recess iSis chamfered or tapered as best seen in fig 1, to match the taper of the lower face 12 of the body 10. Accordingly the shape of the insert 20 engaged in the recess is complementary to the shape of the recess, and the insert 20 blends into the lower and upper tapered faces 11, 12 of the body 10, when secured in the recess 15, as best seen in fig 1, continuing these surfaces without interruption.

The insert 20 typically has a plain aperture extending between its inner and outer faces 21, 22 to receive a threaded fixing such as a bolt, which passes through the insert 20, and engages in a threaded aperture in the face of the recess 15, to secure the insert 20 releasably to the body 10, in a manner than secures the insert 20 in place, but allows its quick removal by loosening the fixing in the event of damage to the insert 20.

Typically the recess 15 has a support wall 16 that is perpendicular to the face of the recess) and perpendicular to the face of the surface 11 to provide a backstop for the insert 20 when secured in the recess, so that forces applied to the insert 20 by the plates when the wedge is driven axially between the plates are transferred to the

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wail 16 rather than to the threaded fixing alone) although the threaded fixing can optionally bear some of the forces applied to the insert 20. Accordingly the insert is buttressed from below and behind by the body, so point loads applied to the insert during operation of the separating tool are spread evenly around the body 10.

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The upper and lower faces 11,12 of the body 10 typically have slots 13 [see Fig 2) extending in line with the axis x-x of the body 10. The upper and lower faces 11, 12 are typically connected by sides. The trailing end of the wedge body lOis typically open to receive a driver device, such as a hydraulic cylinder, although not all examples of the invention need to be hydraulic, and some drivers can comprise a mechanical system with a threaded stem and a captive nut for example.

As shown in Figs 5-17, the wedge body 10 can be used in a wedge tool 1 having at least one plate 30. Two plates 30 [upper and lower) are shown in this example, disposed on opposite upper and lower faces 11, 12 of the wedge body 10. The plates 30 typically have steps and interlocking castellations, and typically have apertures 31 which line up with the slots 13 in the body 10.

The wedge 10 is driven in an axial direction by a hydraulic cylinder 40 having a piston 50, which extends from the cylinder 40 to drive the wedge 10 axially between the plates 30, which causes the plates to move radially apart in opposite directions away from the axis x-x, with a slight axial component as well as radially relative to the axis x-x; in this example, the plates 30 in the direction of the arrows in Fig 7.

The angle of radial movement of the plates 30 relative to the axis x-x is determined by optional retainer arms 41 which extend radially from the body 10, through the slots 13 in the body, and through the apertures 31 in the plates 30, to prevent, or at least restrict, the axial movement of the plates 30 relative to the cylinder 40 while the piston SO is driven axially to move the wedge body 10 along the axis x-x. The arms 41 are mounted on an collar which supports the arms 41 and which has a central bore to receive the piston SO. The collar slots over the piston 50, and is received in the space formed between the side walls extending between the faces 11, 12. Typically the side walls have a profiled inner recess that receives the collar and the cylinder 40, and the arms 41 extend out of the slots 13 in the faces 11, 12.

The collar is prevented from rotation relative to the body 10 by the arms 41 extending through the slots 13, and by the profile of the recess in the space between the side walls.

The arms 41 each have a leading face and a trailing face, which in this example are typically non parallel to one another; the leading face closest to the leading end of the body is typically perpendicular to the axis of the body. Typically the trailing face is perpendicular to the face of the body on which the respective plate is engaged. In certain other examples of the invention, the leading and trailing faces of the arms can be mutually parallel. Typically each plate slides along the trailing face of the arm 41, at the angle defined by the trailing face of the arm 41.

The wedge body 10 slides underneath the plates 30, so that the smooth opposite tapered faces 11, 12 of the wedge body 10 slide along the smooth inner surfaces of the plates 30. The upper face 21 of the insert 20 forms a continuous flat surface with the upper face 11, and the chamfered or tapered lower face 22 likewise forms a continuous flat surface with the lower face 12, so that the plates 30 slide over the insert 20 and wedge body 10 alike, without restriction by the insert 20.

A spring device provided optionally within the bore of the piston 50 is typically held in tension as the piston 50 extends from the cylinder 40, and typically returns the piston to its starting position shown in FigS in the absence of other forces. The plates 30 are typically secured to the body 10 with a T-headed sliding arrangement via bolts 35 and sliders 36, which are secured to the inner surfaces of the plates 30, but which slide under the inner edges of the slots 13 in the body 10, thereby holding the plates 30 onto the tools 1 in the absence of other forces, but allowing the wedge to slide relative to the plates 30 as it advances as a result of the extension of the piston 50.

Typically the body 11 of the wedge is cast, typically from metal such as steel. The insert 20 can also be cast but in this example, the insert 20 is typically formed by machining a piece of rolled forged steel, typically a tool steel or other harder metal as compared with the remainder of the body 10. The insert 20 is typically milled from a flat piece of rolled steel, and typically the leading edge 201 is formed by chamfering it with the same tapered angle as the lower face 12 of the wedge body 10.

As the insert 20 is retained in the recess by a fixing such as a bolt or screw, it can be removed quickly if damaged or worn to permit replacement of the insert 20 in the recess 15 without dis-assembling re-dressing the remainder of the tool, or replacing the body 10. Typically the insert is removed and replaced when it shows signs of wear, for example, bending, scratching, cracking etc. Typically the insert can be removed simply by removing the plate on the recessed face 11, without requiring further dis-assembly of the device.

To facilitate removal and replacement of the insert 20, the tool 1 is placed in the configuration shown in Fig 14, with the insert 20 exposed beyond the limits of the plates 30, and the fixing securing the insert 20 to the recess iSis removed. If the insert 20 becomes buckled or scratched or cracked this can cause irregularities in the surfaces 11, 12, which can affect the freedom of the plates 30 to slide freely over the advancing and retreating wedge body 10, which can worsen any asymmetrical distribution of forces on the plates, increasing the buckling of other components, and increasing the risk of failure under load, potentially causing injury to the user.

Having a replaceable insert 20 means that the insert can be replaced when the damage is minimal, thereby reducing the risks of damaging other parts of the device.

Also, the insert can be formed from a harder material and be less likely to deform under radial loadings applied to the plates 30 at the leading edge, and hence the initial deformation that leads to damage to other components can be avoided or reduced. Furthermore the body 10 can be formed in a single piece from cast material allowing considerable design freedom in selecting different shapes and functions of the body, and greater efficiencies in manufacturing.