A SHIM with an adjusting mechanism, and a method of using same

Abstract

The invention is an adjustable shim, configured from two separate and interlocking discs which, when assembled, are to be fitted onto a shaft. The respective discs, one being an outer half and the other being an inner half, are configured such that their opposing faces have an inner wall that is at or near a central bore that receives the shaft, and an outer wall that is at or near the outer edge of the shim. Both walls of the respective discs have an interior surface and an exterior surface. The exterior surface of the inner wall of the inner half is complementary to the interior surface of the inner wall of the outer half. A section of the outer surface of the wall of the outer half is configured with an opening and bore, with the bore extending through to the interior surface of the wall, resulting in a second opening. The exterior surface of the outer wall of the inner half is configured with a first co-operating surface. A shaft, which contains a head, is provided to the bore and includes a second co-operating surface, a portion of which being exposed at the second opening. The shaft is part of a movement transfer mechanism that converts rotational motion on one axis into rotation motion on another axis. When a user provides rotation via the head of the shaft this causes the inner half of the shim to rotate relative to the outer half of the shim; as such the overall thickness of the adjustable shim may be changed according to the requirements of the user.

Description

[0001] A SHIM WITH AN ADJUSTING MECHANISM, AND A METHOD OF USING SAME

[0002] 1. FIELD OF THE TECHNOLOGY

[0003] The present invention relates to a shim with an adjusting mechanism and a method of using same. The invention has particular application to use in, but not limited to, the heavy engineering industry where rotating shafts of mechanical equipment experience a high level of vibration, which may lead to the wearing of components, and the resultant opening of gaps between same on the shaft.

[0004] 2. BACKGROUND TO THE TECHNOLOGY

[0005] Shafts that bear multiple components, such as bearings and gears, are a key component of energy transfer within various forms of machinery. Shims, or spacers, are commonly used on shafts to ensure correct alignment of said components with complementary components provide to a nearby shaft, or to maintain a desired spacing between adjacent components on the same shaft.

[0006] Conventional shims are typically of a fixed thickness and are selected for use on a shaft with the assumption that there will be no change in dimension of the various components provided to the shaft. However, when exposed to vibration, e.g. in heavy machinery, the spacing along the shaft can change as a result of friction contributing to the wear of components. Alternatively the vibration may cause incremental movement of the component along the shaft. This in turn may result in the changing of thickness, or at least the spatial separation, of the components along the length dimension of the shaft.

[0007] Such changes are problematic as it is preferable that the relative spatial separation between adjacent components be maintain despite wear and tear and any lateral movement arising from vibration action. This is for optimum alignment of the components of the machinery.

[0008] Solutions to this problem have been devised to remediate this issue, one being the use of an adjustable shim that is able to be increased in thickness, through the use of 'steps'.

[0009] One example of this type of shim, is a stepped shim, wherein the shim consists of a series of concentric steps, or levels, with each step having a different thickness. These steps are stacked on top of one another. The appropriate step can be selected based on the desired thickness required. However, a drawback with such a shim is that a finite number of fixed thicknesses are able to be used, which could pose an issue when the desired thickness does not fit an available step.

[0010] Another form of adjustable shim exists in a 'cylindrical belleville washer', wherein this shim is typically conical or cup-shaped, but can also be designed in a cylindrical form with multiple stepped levels joined together. When used on a shaft, the thickness can be selected based on the compressed overall dimension. If a gap were to form on the shaft, it can then 'relax' from its compressed form, and as a result, increase in thickness and close the gap.

[0011] A downside of this type of adjustable shim is that it is automatically adjusting, and as such, it generally does not offer the same control as a manually adjustable device. Secondly, it may be placing unnecessary constant axial load on connecting components, potentially resulting in more wear on the axial faces of these components, reducing their lifespan.

[0012] Another type of adjustable shim is disclosed in United States Patent No. 4433879. This describes an adjustable shim, wherein the shim is configured with a longitudinal split, creating two separable halves. An adjustment means, in the form of serrated cams interacting with a ramp surface, is provided to adjust the thickness of the shim and compensate for gaps forming between components in a shaft. A drawback with the described device is that due to the ramped cam design, the device may pose complexities with manufacture.

[0013] Another example of an adjustable shim is described in United States Published Patent Application No. 2012 / 0082528. This discloses a locking wedge system, wherein the adjustable shim consists of a longitudinal spit, creating two opposing halves with a triangular cross section. Between them is a complementary 'wedge' that is actuated by fasteners, the movement of which allowing the separation of the opposing halves, creating an increase in thickness.

[0014] However, this type of adjustable shim consists of many different moving parts and thus may pose a risk to reliability. Moreover, there is also no means of locking the adjustment fasteners in their set position once the desired shim thickness has been achieved. Hence, this could result in the incorrect thickness if the shim were to adjust due to external vibrations and forces.

[0015] 3. OBJECT OF THE TECHNOLOGY

[0016] It is an object of the technology to provide a shim with an adjusting mechanism, and a method of using same.

[0017] Alternatively, it is an object of the technology to provide an adjusting mechanism for a shim that is easy to use.

[0018] Alternatively, it is an object of the technology to provide an adjusting mechanism for a shim that is cost effective to manufacture.

[0019] Alternatively, it is an object of the technology to provide an adjusting mechanism for a shim that is manually adjustable. Alternatively, it is an object of the technology to provide an adjusting mechanism for a shim that is mechanically reliable.

[0020] At the very least, it is an object of the technology to at least provide the public with a useful choice.

[0021] 4. SUMMARY OF THE TECHNOLOGY

[0022] According to one aspect of the present invention, there is provided an adjustable shim for use with a complementary shaft, wherein the adjustable shim includes: a first member, wherein the first member comprises: a disc having an outer perimeter and an inner perimeter; an inner wall proximate to the inner perimeter of the disc, and wherein the inner wall includes a contact surface; and an outer wall, wherein the outer wall includes a co-operating surface that is concentric to the contact surface of the inner wall; a second member, wherein the second member comprises: a disc having an outer perimeter and an inner perimeter, wherein the inner perimeter defines a central opening for the shaft; an inner wall at or proximate to the central opening, wherein the inner wall includes a contact surface which is configured to be complementary to the contact surface of the inner wall of the first member; and an outer wall, wherein the outer wall includes an exterior side and an interior side, and wherein a bore passes on a tangent through the outer wall from the exterior side to the interior side, and wherein the interior side is provided with an opening communicative with the bore and wherein the interior side is concentric to the contact surface of the outer wall of the first member; an adjustment mechanism provided to the bore of the second member, the adjustment mechanism comprising a movement transfer mechanism which includes: a shaft, wherein the shaft includes a co-operating surface complementary to the cooperating surface of the outer wall of the first member; and wherein, in use, at least a portion of the co-operating surface of the shaft is exposed to and engages with the co-operating surface of the outer wall of the first member at the opening of the first bore on the interior surface of the outer wall of the second member, and wherein the movement transfer mechanism is operable to axially rotate the first member relative to the second member when the respective co-operating surfaces of the shaft of the movement transfer mechanism and first member move with respect to each other.

[0023] The invention is an adjustable shim, which may be configured from two separate and interlocking discs which, when assembled, are to be fitted onto a shaft. The respective discs, one being an outer half and the other being an inner half, are configured such that their opposing faces have an inner wall that is at or near a central bore that receives the shaft, and an outer wall that is at or near the outer edge of the shim. Both walls of the respective discs have an interior surface and an exterior surface. The exterior surface of the inner wall of the inner half is complementary to the interior surface of the inner wall of the outer half.

[0024] A section of the outer surface of the wall of the outer half is configured with an opening and bore, with the bore extending through to the interior surface of the wall, resulting in a second opening. The exterior surface of the outer wall of the inner half is configured with a first co-operating surface. A shaft, which contains a head, is provided to the bore and includes a second co-operating surface, a portion of which being exposed at the second opening. The shaft is part of a movement transfer mechanism that converts rotational motion on one axis into rotation motion on another axis. When a user provides rotation via the head of the shaft this causes the inner half of the shim to rotate relative to the outer half of the shim; as such the overall thickness of the adjustable shim may be changed according to the requirements of the user.

[0025] In one example, the first and second members may be in the form of discs, each disc may be provided with an inner perimeter and outer perimeter that are circular in shape.

[0026] In an additional example, the circular inner and outer perimeters of each member may be concentric.

[0027] In one example, the inner and outer walls may depend downwards from or proximate the inner and outer perimeters of each disc.

[0028] In an additional example, the inner and outer walls of the first member may be located slightly inwards of the inner and outer perimeter of the disc.

[0029] In an additional example, the inner and outer walls of the second member may be located about the inner and outer perimeter of the disc.

[0030] In a further example, the inner walls of each member may be of a diameter such that the contact surface of the inner wall of the first member engages with and is complementary to the contact surface of the inner wall of the second member. In this example, the contact surfaces may be configured with a means of complementarily binding them together. In non-limiting examples, this may be via a helical screw thread pattern on each respective surface.

[0031] In one example, the outer walls of each member may be of diameters such that the co-operating surface of the outer wall of the first member has minimal clearance to the interior side of the outer wall of the second member.

[0032] In one example, a seal may be positioned between or spanning the outer walls of each member.

[0033] In one example, the width of each wall may include a channel or groove which at least partially accommodates the seal.

[0034] In one example, the seal may be a ring-like structure that is compressed when the adjustable shim is closed, and decompresses to fill in the gap between the outer walls of each member when the adjustable shim is opened. In one example, the ring-like structure may be an O-ring.

[0035] In one example, the seal may be a flap or skirt-like structure, which folds inwards when the adjustable shim is closed, and can act to fill the gap between the outer walls of each member when the adjustable shim is opened.

[0036] In one example, the outer perimeters of the first and second member may be provided with a lip, such that a seal can be positioned either side of the lip, providing an external seal from debris and moisture between each member.

[0037] In one example, the seal may be a ring-like structure having substantially C-shaped cross-sectional profile. The first member and the second member may be configured with a lip extending laterally from the circumference of the wall.

[0038] In one example, the outer wall of the first member may include an exterior side and an interior side.

[0039] In this example, the exterior side of the outer wall may include, at least partially, the co-operating surface of the first member. In some examples, the co-operating surface may extend, at least partially, to the interior side of the outer wall of the first member.

[0040] In one example, the co-operating surface of the outer wall of the first member may be a worm wheel.

[0041] In this example, the teeth of the worm wheel may be arranged substantially vertically or are at an angle relative to the exterior of the outer wall, i.e. run from the base of the wall to its top, of the first member.

[0042] In one example, the exterior side of the outer wall of the second member may be configured as the rim of the adjustable shim. In one example, the exterior side of the outer wall of the second member may be configured with at least two slots.

[0043] In this example, the at least two slots may be evenly spaced around the perimeter of the outer wall of the second member.

[0044] In a further example, the at least two slots may extend the full height of the outer wall of the second member.

[0045] In one example, the exterior side of the outer wall may be configured with at least two indentations.

[0046] In this example, at least two indentations may be evenly spaced around the perimeter of the outer wall of the second member.

[0047] In a further example, the at least two indentations may extend the full height of the outer wall of the second member.

[0048] In a further example, the at least two indentations may be spaced such that the spacing is substantially complementary to the spacing of the at least two slots on the exterior side of the outer wall of the second member.

[0049] In one example, the outer wall may include a blind bore extending from an opening provided to the exterior side of the outer wall on a tangent to the outer perimeter of the second member. In another example, the outer wall may include a bore extending from an opening provided to the exterior side of the outer wall on a tangent to the outer perimeter of the second member to another opening to the exterior side of the outer wall.

[0050] In one example, at least a portion of the side of the bore may open onto the interior side of the outer wall.

[0051] In one example, wherein the bore is a first bore and a second bore is provided to the outer wall, extending from an opening provided to the exterior side of the wall to a side of the first bore. In a particularly preferred example, the second bore may be perpendicular to the first bore.

[0052] The adjustment mechanism should be understood to be or includes a movement transfer mechanism that is configured with a shaft and a head. In use, at least the shaft of the adjustment mechanism may be disposed within the bore. At least a portion of the shaft may be configured with a co-operating surface that is complementary to that of the outer wall of the first member.

[0053] In one example, a seal may be positioned in a shaft groove between the head and the co-operating surface of the shaft. In one example, the seal may be a ring-link structure, such as an O-ring or washer. In one example, the co-operating surface of the shaft may be a worm or worm drive. This will be understood to contain a substantially helical thread.

[0054] In a particularly preferred example, the adjustment mechanism may be positioned within the bore such that the co-operating surface that is provided to the shaft may be exposed and proud of the opening provided to the interior side of the outer wall of the second member.

[0055] In an example, the head of the adjustment mechanism may be configured to receive a working tool

[0056] In this example, the head may be provided with a recessed hex structure, which receives the end of a hex tool for rotation of the adjustment mechanism. In other non-limiting examples, the head may be provided or otherwise configured to receive a flat head, Philips, Pozzi or similar screwdriver or another tool.

[0057] In use, rotation of the adjustment mechanism may lead to the engagement of the movement transfer mechanism means via a transfer of energy from the co-operating surface of the adjustment mechanism to the co-operating surface of the outer wall of the first member. The transfer of energy may result in rotation of the first member relative to the second member. The rotation may result in the axial movement of the first and second member, as defined by the pattern on each of their inner wall complementary surfaces.

[0058] In one example, a portion of the shaft, between the head and co-operating surface may consist of a locking surface. In a particularly preferred example, the locking surface may be of a hexagonal or square configuration wherein the major diameter of the hexagonal / square configuration is less than the diameter of the first bore.

[0059] In one example, a portion of the shaft, between the head and the locking surface, may consist of an unlocking surface. In a particularly preferred example, the un-locking surface may be of a circular configuration wherein the major diameter of this circular configuration is less than the major diameter of the locking surface.

[0060] In one example, a locking member may be provided to the second member, via the second bore in the outer wall of the second member.

[0061] In one example the second bore may be configured with a locking member, wherein a portion of the locking member may contact the locking surface of the adjustment mechanism that is deposited within the first bore, thereby prevent rotation of the adjustment mechanism.

[0062] In a particularly preferred example, the locking member may be a set screw with a diameter less than that of the second bore. In one example, the bore in the outer wall of the second member may be configured to receive a biasing member. In use, the biasing member may bear against the shaft of the second co-operating surface, thereby providing force to resist the motion of the movement transfer mechanism.

[0063] In a particularly preferred example, the biasing member may be a spring. In another example, the biasing member may be a block of compressible material, such as an elastomer or the like.

[0064] In this example, the biasing member may possess a diameter that is less than that of the bore.

[0065] It will be understood that in operation, when the locking surface of the adjustment mechanism is released from the locking member by force against the biasing member, and then rotated in a first direction, the co-operating surface of same contacts the co-operating surface provided to the exterior side of the outer wall of the first member, resulting in the first and second member of the adjustable shim separating axially along the shaft, as limited by the complementary thread pattern of the respective surfaces on the inner wall of the first and second member. When the adjustment mechanism is released, the locking surface on the adjustment mechanism resumes contact with the locking member, preventing further rotation and thereby maintaining the position of the first and second member. When the locking surface of the adjustment mechanism is released from the locking member by force against the biasing member, and the adjustment mechanism is rotated in the opposing direction, the first and second members of the adjustable shim rejoin, as limited by the complementary thread pattern of the respective surfaces on the inner wall of the first and second members.

[0066] According to another aspect of the present invention, there is provided a method of using an adjustable shim substantially as described above, the method including the steps of: a) engaging the contact surfaces of the inner wall of the first and second member; and b) rotating the first and second members relative to each other by engaging the co-operating surface of the member with the co-operating surface of the adjustment member.

[0067] In one example, step b) involves applying: i) a downwards motion to the adjustment mechanism,; and ii) a rotary motion, wherein the adjustment mechanism includes an engagement means for a tool to apply said motion.

[0068] In this example, the tool could be a hex key, Allen key or other device known to those skilled in the art and suitable for applying a rotational force to the engagement means.

[0069] In another example, the sequence of i) and ii) may be reversed. In one example, the process of step b) may be achieved by rotating a co-operating surface of the adjustment mechanism against a complementary co-operating surface of the outer wall of the first member, forcing the inner walls of each member to rotate about their contact surfaces, which may lead to the axial movement of each of the members, relative to each other.

[0070] In one example, step b) may involve releasing the downward motion at a point wherein the locking surface has sufficient contact area for the locking member to engage.

[0071] 5. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] One or more embodiments of the technology will be described below byway of example only, and without intending to be limiting, with reference to the following drawings, in which:

[0073] Figure 1 is an isometric view of an adjustable shim in accordance with one aspect of the present invention;

[0074] Figure 2 is an isometric view of the outward side of a first member forming the adjustable shim of Figure 1;

[0075] Figure 3 is an isometric view of the internal components of the inwards side of a second member forming the adjustable shim of Figure 1;

[0076] Figure 4 is an exploded isometric view of the second member of Figure 3 and adjustment mechanism;

[0077] Figure 5 is a cross-sectional plan view of the adjustable shim of Figures 1;

[0078] Figure 6 is a cross-sectional side detail view of the adjustment mechanism of the adjustable shim of Figure 1;

[0079] Figure 7 is an isometric view of an adjustable shim in accordance with another aspect of the present invention;

[0080] Figure 8 is a detail section view of the adjustable shim of Figure 7;

[0081] Figure 9 is an isometric view of an adjustable shim in accordance with another aspect of the present invention;

[0082] Figure 10 is an isometric view of the first member forming the adjustable shim of Figure 9; and

[0083] Figure 11 is an isometric view of the second member forming the adjustable shim of Figure 9. 6. DETAILED DESCRIPTION OF EXEMPLARY FORMS OF THE TECHNOLOGY

[0084] 6.1. Adjustable Shim

[0085] An example of the invention in the form of an adjustable shim (generally indicated by arrow 100) is depicted in an isometric view in Figure 1. The adjustable shim may be used with a complementary shaft, not shown here. The adjustable shim takes a substantially disc-like form but is comprised of a first disc member 200 and a second disc member 300 (the first and second members henceforth).

[0086] In Figure 1, the first member 200 forms one side of the adjustable shim 100, with the outward surface being substantially flat. The second member 300 forms the other side of the adjustable shim and its outward surface (not visible in Figure 1) is substantially flat. In use, the respective outward surfaces would abut other components mounted to the same shaft as the adjustable shim.

[0087] Each member has an inner perimeter and an outer perimeter. In the illustrated example, the adjustable shim includes a central bore CB, which in use receives the complementary shaft to which the invention is mounted. This bore is defined by the inner perimeters 202,302 of the respective first 200 and second 300 members.

[0088] As shown, the central bore CB is circular and provided to the centre portion of the adjustable shim 100, but those skilled in the art will appreciate that it may be off-centre and could be comprised of any shape, provided it was complementary to the cross-sectional shape of the shaft. However, as will become apparent from the following description, the mating or contact surfaces of the respective first 200 and second 300 members would still need to be circular in a plan view in order to achieve the functionality of the invention.

[0089] Each member is provided with inner and outer concentric walls at or proximate its inner 202.302 and outer perimeters 204,304 (in Figure 1, only the outer wall 306 of the second member 300 is visible, that of the first member 200 being internal to the adjustable shim 100).

[0090] Each wall has an interior and exterior surface; in Figure 1, the exterior surface 308 of the inner wall 310 of the second member 300 forms the substantial portion of the central bore CB while the exterior surface 312 of the outer wall 306 of the second member forms a substantial portion of the edge of the adjustable shim 100. It will be appreciated from this that the bulk of the overall thickness of the adjustable shim is provided by the relative height of the outer wall of the second member.

[0091] The exterior surface 312 of the outer wall 306 of the second member 300 includes slots 313. In use, these slots receive or otherwise engage a tool to rotate the second member relative to the first member 200.As can be seen, the outer wall 306 of the second member 300 is shown to have a bore 314 fitted with an adjustment mechanism 316. This bore enters the exterior surface 312 of the outer wall 306 of the second member and exits, or at least opens onto, the interior surface of the outer wall (not visible in Figure 1).

[0092] The adjustment mechanism 316 includes a body 318, that is preferably made of steel or another suitable metal alloy, consisting of a head, with a shaft (obscured in Figure 1) depending downwards from same. In the exemplified example, the head is configured as a conventional hex head but those skilled in the art will appreciate that the head of an adjustment mechanism can come in various forms such as, in nonlimiting examples, square, round, slotted, Phillips, Allen, button, cap and wing, among others.

[0093] The features and operation of the invention will be better understood from the ensuing discussion of Figures 2 to 6.

[0094] 6.2. First and Second Member

[0095] The first 200 and second member 300 are depicted in Figure 2 and Figure 3 respectively. Referring now specifically to the first member, as seen in Figure 2, this assumes a substantially disc or plate-like form. The side substantially visible here, i.e. the outer side, serves as one of the outward surfaces of the adjustable shim 100; in use this would contact the adjacent components mounted to the complementary shaft, whether these be other shims, spacers, gears or such like. The inner side, in use, faces the inner side or surface of the second member.

[0096] The first member 200 has concentric inner 202 and outer 204 perimeters as shown. It will be appreciated that the inner perimeter of the first member at least partially defines the central bore CB that receives the complementary shaft to which the invention is to be mounted. However, the inner perimeter is substantially chamfered, such that when the adjustable shim 100 is assembled, the inner perimeter has substantially little or no contact with the shaft to which the adjustable shim is mounted.

[0097] Slightly inwards or proximate the respective inner 202 and outer 204 perimeters are provided concentric inner 206 and outer walls 208 depending downwards from the inner side (not visible in this view). This configuration means that the inner and outer perimeter slightly overhands the inner and outer walls.

[0098] These inner 206 and outer walls 208 have an exterior surface 210,212 or side that faces the respective inner 202 and outer perimeters 204 while the respective interior surfaces (not shown in Figure 2) of the sides of the inner 206 and outer walls 208 face each other.

[0099] As already noted, the first member 200 of Figure 2 has an outer perimeter 204 that is shown to be circular and concentric to the inner perimeter 202. However, those skilled in the art will understand that is some examples, the outer perimeter may be configured in a different shape and does not have to be concentric to the inner perimeter. The inner wall 206 of the first member 200 includes an exterior surface 210 configured to be complementary with or to the corresponding surface of the second member 300 (not shown). These will be understood to form the contact surfaces of the first and second members.

[0100] In the example of Figure 1, this contact surface 210 is threaded, the corresponding surface of the second member 300 (not shown) having a complementary thread. It should be appreciated that the thread pattern shown on the said surface is not meant to be limiting and other forms are readily envisaged. In non-limiting examples, the interior surface of the inner wall 206 could contain one or more of the following thread patterns: UTS, metric, Whitworth, Acme, trapezoidal, buttress, square, knuckle, triangular and spline, among others.

[0101] It will be understood that the adjustable shim 100 is assembled by threading these contact surfaces together. The extent to which these are threaded together determine the relative thickness of the adjustable shim.

[0102] The exterior surface 212 of the outer wall 208 of the first member 200 is configured with a co-operating surface 214; in the example of Figure 2, this is a worm wheel or gear, with the thread or teeth arranged substantially vertically, relative to the outer wall. This is part of the adjustment mechanism of the invention, intended to allow the thickness of the adjustable shim 100 to be altered as required. Those skilled in the art will appreciate that the co-operating surface may me in various forms such as, in nonlimiting examples, cam locks or sliding ramps, among others.

[0103] The second member 300 forming the adjustable shim 100 of the present invention is shown in Figures 3 and 4. The former shows the adjustment mechanism in place while the latter shows the adjustment mechanism externally of the second member.

[0104] In both Figures 3 and 4, the inner side of the second member 300 is visible, clearly showing the inner wall 310. In use, the outer side, not visible in this view but facing downwards, would abut other components mounted to the same shaft as the adjustable shim.

[0105] The exterior surface 308 of the inner wall 310, which depends directly downwards from the inner perimeter 302 of the second member 300, forms a substantial portion, if not the entirety, of the central bore CB that contacts the complementary shaft with which the adjustable shim 100 is to be used. The interior surface 320 of the inner wall is, as will already be apparent, the contact surface that is threaded to be complementary to the contact surface of the inner wall of the first member (not shown).

[0106] Note that due to the need to confer the ability to allow the rotation of the first member 200 relative to the second member 300, the interior surface 320 of the inner wall 310 of the second member 300 and the exterior surface 210 of the inner wall 206 of the first member 200 must be circular. This is best seen in Figure 5.

[0107] Returning to Figures 3 and 4, it will be seen that the outer wall 306 depends directly downwards from the outer perimeter 304 of the second member 300. The outer wall, in use, substantially forms the rim of the adjustable shim 100. The height of this outer wall, and that of the inner wall 310, substantially correlates to the overall thickness of the adjustable shim, although it will be appreciated that a small proportion may be contributed by the first member 200.

[0108] The interior surface 322 of the outer wall 306 is substantially smooth. This is particularly important so as to minimise any frictional interference between it and the co-operating surface 214 of the outer wall 208 of the first member 200. As seen in Figure 5, there is a slight clearance between the respective interior and exterior surface of the outer wall. It will also be appreciated that to allow the rotation of the first member 200 relative to the second member 300, the interior surface of the outer wall of the second member and the exterior surface 212 of the outer wall of the first member must be substantially circular.

[0109] As can be seen in Figures 1, 3 and 4, the exterior surface 312 of the outer wall 306 of the second member 300 is configured with a plurality of vertical notches 324. This is beneficial as it provides a high friction surface for the users hand when actuating the adjustable shim. In examples not shown, this surface may be configured with any other means apparent to those skilled in the art to provide friction to the surface such as, in non-limiting examples knurling, abrasive basting, grinding, sanding, among others.

[0110] Running tangentially through at least a portion of the outer wall 306 is a bore 314, the opening 326 on the outer perimeter best seen in Figure 4. The orientation and alignment of the bore is such that a portion 328 of the length of the bore opens out onto the interior surface 322 of the outer wall. This bore receives the adjustment mechanism 316.

[0111] Note that the bore 314, as shown in Figure 5, does not pass entirely through the outer wall 306; it remains closed at its far end. However, in some examples not shown here, the bore may extend right the way through; this may simplify manufacture of the invention.

[0112] 6.3. Adjustment Mechanism

[0113] The components of the adjustment mechanism 316 are best seen in Figures 4 to 6, and include the adjustment mechanism itself, and a biasing member 330, which in use are located internally of the first bore 314 provided to the outer wall 306 of the second member 300, and a locking member 332, which in use is located in a second bore 334 that is perpendicular to the first bore.

[0114] Dealing first with the adjustment mechanism 316, this is in the form of a shaft 318 with a head 336 at one end. The head is configured with an engagement means 338 for attachment of a tool. In the form shown, the engagement means is a hexagonal opening which receives the end of a hex / Allen key or drill bit. Other forms of engagement means will be readily envisaged by the skilled addressee.

[0115] The shaft 318 is configured with three different surfaces provided in the following order, depending longitudinally downward from the head 336; an un-locking surface 340, a locking surface 342 and a cooperating surface 344.

[0116] In the example shown, the locking 342 and unlocking 340 surfaces have a major diameter that is less than that of the head 336, and their longitudinal dimension is shown to be similar to that of the head. These relative sizes are by no means meant to be limiting, and those skilled in the art will appreciate that the relative diameters and longitudinal dimensions could differ.

[0117] A substantial portion of the shaft 318 is configured with a co-operating surface 344 that is complementary to that of the first member 200 (not shown). As noted in respect of Figure 2, the co-operating surface 214 of the first member is a worm wheel; the co-operating surface 344 of the adjustment mechanism 316 is a worm or worm drive, i.e. a gear with a helical thread. Those skilled in the art will appreciate that the illustrated thread of the adjustment mechanism is by no means meant to be limiting; so long as it is complementary to the co-operating surface of the first member.

[0118] The biasing member 330 is provided to the base of the first bore 314 on the outer wall 306 of the second member 300. When compressed by the adjustment mechanism 316, the biasing member urges the adjustment mechanism towards the exterior surface 312 of the outer wall of the second member, providing a locking function.

[0119] In the examples shown, the biasing member 314 is an expansion / compression spring. However, this is not meant to be limiting, and those skilled in the art will appreciate that biasing members can come in various forms such as a rubber or other elastomer block, among others.

[0120] Figure 6 illustrates the locking member 332 provided to the outer wall 306 of the second member 300, via a second bore 334 in the outer wall of the second member. In the illustrated example, the second bore is perpendicular to and communicative with the first bore 314 that receives the adjustment mechanism 316 and has an opening 346 on the lower side 348 of the second member.

[0121] When engaged, the locking member 332 serves to prevent operation of the adjustable shim 100, i.e. prevent rotation of the first 200 and second members 300 with respect to each other. When disengaged, the adjustment mechanism 316 is able to be rotated, such rotation of the first and second members is possible, i.e. the thickness of the adjustable shim may be increased (or decreased) as required. In Figures 4 to 6, the locking member 332 is shown to be a set screw. This is not intended to be limiting, and those skilled in the art will understand that the locking member could come in various forms including a threaded inset or grub screw, among others.

[0122] In the example shown in Figure 6, the locking surface 342 is shown as a hexagonal portion of the shaft 318, with a circular base 350, located directly proximal to the co-operating surface 344. The adjustable shim 100 is shown to be in a locked position, with the biasing member 330 in an uncompressed state, and the locking member 332 bearing against the locking surface. The multiple sides on the hexagonal portion of the locking surface restrict the level of incremental adjustment which is possible through actuation of the adjustment mechanism 316, and provide a platform for the lateral surface of the locking member to engage. The circular base provides a contact point for a longitudinal portion of the locking member to engage, due to the urging of the biasing member, when the biasing member is in a non-compressed state.

[0123] Persons skilled in the art will understand that the hexagonal portion of the locking surface 342 could be any shape, provided at least one surface is available for engagement with the locking member 332. The circular base 350 could also be of any shape such that it can provide a surface for the longitudinal portion of the locking member to engage.

[0124] The unlocking surface 340 is shown in Figure 6 as a cylindrical portion of the shaft 318, immediately proximate to the head 336. Persons skilled in the art will understand that the unlocking surface could be any shape, provided that the major diameter of same is less than that of the minor diameter of the locking surface 342.

[0125] In a compressed position, the adjustment mechanism 316 is pushed further into the first bore 314, against the biasing member 330, such that the locking member 332 releases contact with the locking surface 342 and becomes aligned with the unlocking surface 340. The locking member is adjusted such that when it is aligned with the unlocking surface, there is no contact between the locking member and the unlocking surface, allowing rotation of the adjustment mechanism.

[0126] Figure 7 shows another embodiment of the invention 100, with an alternative configuration of the first member 201. In this example, the first member 201 is shown with evenly spaced indentations 205 provided to the alternative outer perimeter 207. These indentations may be used for the purpose of aiding rotation of the first member, and that they could be of any profile or shape, and of any spacing, provided that this corresponds with an appropriate tool as will be recognised by persons skilled in the art.

[0127] The spacing of the indentations 205 on the outer perimeter 207 of the first member 201 may substantially complement the spacing of the slots 313 provided to the exterior surface 312 of the outer wall 306 of the second member 300. Persons skilled in the art that the use of these indentations may also be applied the embodiment previously described in respect of Figures 1 to 6.

[0128] 6.4. Sealing arrangements

[0129] Figures 7 to 11 show an alternative embodiment of the invention 100, with the addition of a sealing arrangement. The presence of a seal may be useful in preventing or reducing the possibility of moisture and detritus from entering the internals of the adjustable shim of the present invention.

[0130] The embodiment of the invention 100 shown in Figure 7 includes a seal 400, positioned between the outer perimeter 204 of the first member 200 and the outer perimeter 304 of the second member 300.

[0131] Figure 8 shows a detailed section view of the embodiment shown in Figure 7, with the seal 400 (shown overscale for illustrative purposes) provided between the outer perimeter 204, 304 of the first member 200 and the second member 300. In this example, the seal is shown to be an O-ring. However, this is not meant to be limiting, as other sealing forms may be used to seal the gap between the first and second member may be envisaged, such as a flap, or gasket.

[0132] In the illustrated example, the seal is positioned within a groove 402 within the outer wall 306 of the second member 300, which ensures it is retained. When the adjustable shim 100 is closed, the seal is compressed into the groove 402, such that it substantially conforms to the shape of the groove. In this example, the groove is shown to be a substantially rectangular cross-section. However, it should be appreciated that this may take any shape appropriate to retain the seal, such as semi-circular or even triangular.

[0133] A further seal (not visible) may be provided to the locking member 332. This seal (not visible) may be in the form of a O-ring or similar, and located behind the head 334 of the locking member 332, or partway down its shaft. The presence of this O-ring helps prevent or reduce possibility of debris / detritus and / or moisture from entering the internals of the adjustable shim via the locking member.

[0134] Figures 9 to 11 show an alternative embodiment of the invention 100, configured with an alternative sealing arrangement in the form of a skirt 404 covering a portion of the outer perimeter of the first member 200 and second member 300, particular the region where the respective members meet each other. In this example, the sealing arrangement 404 is external to the adjustable shim 100, compared to the sealing arrangement of Figures 7 and 8, which may be considered to be, partially at least, internal to the adjustable shim.

[0135] In the example of Figures 9 to 11, a first lip or flange 209 extends away from the outer perimeter 204 of the first member 200 of the adjustable shim 100. Similarly, a second lip or flange 309 is provided to the outer perimeter 304 of the second member 300. As best understood from Figure 9, the skirt 404 is of a C-shaped profile that engages with the respective lips 209, 309; as the distance between the respective members 200, 300 increase, the skirt stretches to prevent the internals of the adjustable shim from being exposed to debris and / or moisture.

[0136] 6.5. Use of the invention

[0137] As will be evident from the prior discussion, the usage of the invention is simple. The two members 200,300 of the adjustable shim 100 are mated together, and then the adjustment mechanism 316, serving as a movement transfer mechanism, is actuated as required to increase its thickness.

[0138] As the head 336 of the adjustment mechanism 316 is pressed into the first bore 314 through the use of a tool, such as an Allen key, this causes the shaft 318 to compress the biasing member 330, resulting in the locking member 332 disengaging from the locking surface 342, and aligning with the unlocking surface 340. The user can then use the tool in the head of the adjustment mechanism to rotate same. As the cooperating surface 344 of the shaft is engaged with the co-operating surface 214 of the outer wall 208 of the first member 200, the adjustment mechanism 316 transfers the rotational movement of the shaft into rotational movement of the first member relative to the second member 300.

[0139] Following the disengaging of the adjustment mechanism 316, the user can then apply a rotational force, which may be in a clockwise or anti-clockwise direction depending on the configuration of the cooperating surfaces, to the head 336 of same to form contact between the first 214 and second 344 cooperating surfaces. Rotational movement of the cooperating surface on the adjustment mechanism, i.e. the worm, is then transferred to rotational movement of the cooperating surface on the outer wall 208 of the first member 200, i.e. the worm wheel. This movement transfer results in the helical thread on the adjustment mechanism and the worm wheel on the first member rotating relative to each other. As this rotation occurs, the complementary thread on the inner walls 206,310 of each member unwind, resulting in the increase in thickness of the adjustable shim 100. The invention can of course be used in reverse to decrease the width of the adjustable shim, assuming there is sufficient clearance to do so.

[0140] The removal of the force on the head 336 of the adjustment mechanism 316 causes same to retreat from the first bore 314, assisted by the spring 330 acting against same. A minor rotation of the head of the adjustment mechanism may be required upon release of the inwards force, such that the locking surface 342 is re-aligned with the locking member 332.

[0141] The invention is advantageous in that it provides a means of adjusting a shim relative to the shaft with which it is to be used that is manually operable via a rotational action rather automatically expanding. This adjustment is able to be performed while the adjustable shim 100 is still mounted to the shaft since the user only needs access to the rim of the shim, so as to operate the adjustment mechanism 316 with a tool, rather than its contact surfaces (which may be contacting adjacent components on the shaft).

[0142] In some situations, the ability to manually adjust the thickness of the shim 100 may be more appropriate as it may apply less axial force to the components on the shaft; this could potentially reduce stress and wear on the respective components. Additionally, in preferred embodiments, the adjustment mechanism 316 automatically locks in place after use, greatly simplifying its operation.

[0143] From a manufacturing perspective, the present invention is advantageous in being simpler, and therefore more cost-effective, to manufacture. This is due to the simplicity of its arrangement which does not require multiple sliding ramps of cam mechanisms, such as those commonly found in the prior art.

[0144] 6.6. Other Remarks

[0145] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

[0146] The entire disclosures of all applications, patents and publications cited above, if any, are herein incorporated by reference.

[0147] Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.

[0148] The technology may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

[0149] Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

[0150] It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the technology and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present technology.

Claims

7. CLAIMSWhat we claim is:

1. An adjustable shim for use with a complementary shaft, wherein the adjustable shim includes: a first member, comprising: a disc having an outer perimeter and an inner perimeter; an inner wall proximate to the inner perimeter, wherein the inner wall includes a contact surface; and an outer wall, including a co-operating surface that is concentric to the contact surface; a second member, comprising: a disc having an outer perimeter and an inner perimeter, wherein the inner perimeter defines a central opening for the complementary shaft; an inner wall at or proximate to the central opening, wherein the inner wall includes a contact surface which is configured to be complementary to the contact surface of the inner wall of the first member; and an outer wall, including an exterior side and an interior side, and wherein a bore passes on a tangent through the outer wall from the exterior side to the interior side, and wherein the interior side is provided with an opening communicative with the bore and wherein the interior side is concentric to the contact surface of the outer wall of the first member; an adjustment mechanism provided to the bore of the second member, the adjustment mechanism comprising a movement transfer mechanism which includes: a shaft, including a co-operating surface complementary to the co-operating surface of the outer wall of the first member; and wherein, in use, at least a portion of the co-operating surface of the shaft is exposed to and engages with the co-operating surface of the outer wall of the first member at the opening of the first bore on the interior surface of the outer wall of the second member, and wherein the movement transfer mechanism is operable to rotate the first member relative to the second member when the respective co-operating surfaces of the shaft of the movement transfer mechanism and first member move with respect to each other.

2. The adjustable shim as claimed in claim 1, wherein the first and second members are in the form of circular discs.

3. The adjustable shim as claimed in either claim 1 or claim 1, wherein the outer and inner perimeters of each disc, and consequently the respective walls of each disk, are circular in shape.

4. The adjustable shim as claimed in any of claims 1 to 3, wherein the inner and outer perimeters of each disk, and consequently the respective walls of each disk, are concentric.

5. The adjustable shim as claimed in any one of claims 1 to 4, wherein the complementary contact surfaces of the first member and the second member are helical screw threads.

6. The adjustable shim as claimed in any one of claims 1 to 5, wherein the co-operating surface of the outer wall of the first member is a worm wheel.

7. The adjustable shim as claimed in any one of claims 1 to 6, wherein the shaft consists of a first and second portion.

8. The adjustable shim as claimed in claim 7, wherein a first segment of the first portion of the shaft consists of a locking surface.

9. The adjustable shim as claimed in claim 8, wherein the locking surface is a hexagonal configuration.

10. The adjustable shim as claimed in claim 7, wherein a second segment of the first portion of the shaft consists of an un-locking surface.

11. The adjustable shim as claimed in claim 10, wherein the un-locking surface is a circular configuration.

12. The adjustable shim as claimed in claim 7, wherein the co-operating surface of the adjustment mechanism of the movement transfer mechanism is provided to the second portion of the shaft.

13. The adjustable shim as claimed in claim 12, the co-operating surface of the adjustment mechanism of the movement transfer mechanism is a worm or worm drive.

14. The adjustable shim as claimed in claim 13, wherein a groove is provided to the shaft.

15. The adjustable shim as claimed in claim 14, wherein a seal is provided to the groove.

16. The adjustable shim as claimed in any one of claims 1 to 15, wherein the bore is a first bore and there is a second bore that is perpendicular to, and communicative with, the first.

17. The adjustable shim as claimed in claim 16, wherein a locking mechanism is provided to the second bore.

18. The adjustable shim as claimed in claim 17, wherein the locking mechanism is a set screw.

19. The adjustable shim as claimed in any one of claims 1 to 18, wherein in use, rotation of the adjustment mechanism leads to the engagement of the movement transfer mechanism meansvia a transfer of energy from the co-operating surface of the adjustment mechanism to the cooperating surface of the outer wall of the first member.

20. The adjustable shim as claimed in any one of claims 1 to 15, wherein the bore is configured to receive a biasing member.

21. The adjustable shim as claimed in claim 20, wherein the biasing member is a spring.

22. The adjustable shim as claim in any one of claims 1 to 21, wherein a sealing arrangement is provided to cover at least a portion of the outer perimeters of the first and second members.

23. The adjustable shim as claimed in any one of claims 1 to 21, wherein a sealing arrangement is provided between the outer perimeters of the first and second members.

24. A method of using an adjustable shim for use with a complementary shaft, the adjustable shim as claimed in any one of claims 1 to 23, the method including the steps of: a) engaging the contact surfaces of the inner wall of the first and second member; and b) rotating the first and second members relative to each other by engaging the cooperating surface of the member with the co-operating surface of the adjustment member.

25. The method as claimed in claim 24, wherein step b) involves applying: i) a downwards motion to the adjustment mechanism,; and ii) a rotary motion, wherein the adjustment mechanism includes an engagement means for a tool to apply said motion.

26. The method as claimed in claim 25, wherein the sequence of i) and ii) may be reversed.

27. The method as claimed in claim 25 or claim 26, wherein the tool is a hex key, Allen key, screwdriver, drill bit, or rachet.

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