Tool assembly

Abstract

A handheld tool assembly for measuring and marking has a body 102 and blade 104 that can have their relative angular and translational position adjusted, with a locking assembly 106 having a locking m

Description

FIELD OF THE INVENTION The present invention relates to tools such as handheld measuring and marking tools. In particular the present invention relates to a tool assembly comprising a locking assembly for securing relative positions of parts of the tool assembly. BACKGROUND TO THE INVENTION A handheld tool known as a square, try square, or carpenter’s square comprises a first part which may be referred to as a stock, and a second part comprising a blade or tongue fixed to the stock so that a straight edge of the blade extends perpendicular to a straight edge of the stock. A square is used to check and mark 90-degree angles during construction tasks such as carpentry work, by placing the edges of the stock and / or blade against surfaces of a workpiece. To measure or mark a range of different angles, it is known to use a tool which may be known as an angle finder, comprising a first part having a straight edge and a second part having a straight edge and being pivotally mounted to the first part. In use, the first part is pivoted with respect to the second part to set a desired angle between the straight edges of the first and second parts. The angle may be indicated by a gauge provided on one of the parts. To secure an angular position of the first part with respect to the second part, a simple clamping mechanism may be used. In particular, the first and second parts may be mounted to pivot on the shank of a bolt, and a nut may be used to clamp the first and second parts together between the nut and a head of the bolt, to fix the relative angular position of the first and second parts. A problem with this arrangement is that tightening of the nut may result in relative movement of the parts, causing an unwanted change in the angle between the edges of the parts. Also, friction between the nut or bolt and one of the parts can cause unwanted tightening of the nut and bolt whilst pivoting the first and second parts to set a desired angle, causing the first and second parts to seize at an arbitrary angle. Accordingly, such tools may be inconvenient to use and / or inaccurate. It is against this background that the present invention is devised. It is an object of the present invention to overcome at least one problem associated with the prior art, whether referred to herein or otherwise. SUMMARY OF THE INVENTION According to a first aspect of the invention there is provided a tool assembly for a handheld tool, the tool assembly comprising: a first tool member; and a second tool member; wherein the first tool member is mounted to pivot with respect to the second tool member about a pivot axis for adjusting an angular position of the first tool member with respect to the second tool member; and wherein the first tool member is mounted for translational movement with respect to the second tool member, for adjusting a translational position of the first tool member with respect to the second tool member; the tool assembly further comprising a locking assembly comprising: a first locking arrangement for securing the translational position of the first tool member with respect to the second tool member, the first locking arrangement being operable between an unlocked configuration in which the first tool member may translate with respect to the second tool member, and a locked configuration in which the translational position of the first tool member with respect to the second tool member is secured; and a second locking arrangement for securing the angular position of the first tool member with respect to the second tool member, the second locking arrangement being operable between an unlocked configuration in which the first tool member may be pivoted about said axis with respect to the second tool member, and a locked configuration in which the angular position of the first tool member with respect to the second tool member is secured; wherein, with the second locking arrangement in the unlocked configuration, the first locking arrangement is arranged to turn with the first tool member, with respect to the second tool member; and preferably wherein the first locking arrangement is operable independently of the second locking arrangement. In this way, an angular position and a translational position of the first tool member with respect to the second tool member may each be adjusted and set independently of the other. For example, the translational position of the first tool member with respect to the second tool member may secured by the first locking arrangement whilst the first tool member remains free to pivot with respect to the second tool member. Or conversely the angular position of the first tool member with respect to the second tool member may be secured by the second locking arrangement whilst the first tool member remains slidably moveable relative to the second tool member. In this way the second locking arrangement is configured to be operable between the (first) unlocked configuration in which the first tool member may be pivoted with respect to the second tool member and the (second) locked configuration in which the angular position of the first tool member with respect to the second tool member is secured. Preferably the first tool member is slidably mounted with respect to the second tool member. The first tool member may be arranged to move in a direction (or plane) substantially perpendicular to the pivot axis. The first tool member may be constrained to move in a single plane, which may be substantially perpendicular to the pivot axis. When the second locking arrangement is in the unlocked configuration, the locking assembly may be arranged to turn with the first tool member. The locking assembly may be mounted to the second tool member to turn with respect to the second tool member. In this way the first locking arrangement is configured to be operable between a (first) unlocked configuration in which the first tool member may translate (e.g., slide) with respect to the second tool member and a (second) locked configuration in which the translational position of the first tool member with respect to the second tool member is secured. Preferably the first tool member is constrained for movement in a (single) plane with respect to the second tool member. Preferably the locking assembly is configured to mount the first tool member to the second tool member. With this arrangement, the tool assembly is particularly compact, because the locking assembly both acts to secure the relative positions of the first and second tool members, and also mounts the first tool member to the second tool member. The locking assembly may be arranged coaxially with the pivot axis. The first locking arrangement may be arranged coaxially with the pivot axis. The second locking arrangement may be arranged coaxially with the pivot axis. Preferably the first locking arrangement and the second locking arrangement are arranged coaxially with the pivot axis. In this way both the first and second locking arrangements may be arranged to turn about a common axis. These arrangements help to provide a compact tool assembly. The second locking arrangement may be configured, in the locked configuration, to urge the second tool member against part of the second locking arrangement such that frictional engagement between the second locking arrangement and the second tool member resists pivoting of the first tool member with respect to the second tool member. The tool assembly may comprise a frictional element arranged to be clamped between the second locking arrangement and the second tool member to provide (or increase) a frictional force between the second locking arrangement and the second tool member. The frictional element may be engaged with the second locking arrangement and with the second tool member when the second locking arrangement is in the locked configuration and when the second locking arrangement is in the unlocked configuration. In this way, the frictional element may help to maintain a degree of friction to resist pivoting of the first tool member with respect to the second tool member when the second locking arrangement is operated towards the unlocked configuration and / or when the second locking arrangement is in the unlocked configuration. Preferably the frictional element comprises a resiliently deformable element. Preferably the frictional element is substantially annular. The frictional element may comprise a resilient O-ring. The frictional element may be mounted in a groove in the second tool member. The frictional element may extend around the pivot axis. The first locking arrangement may comprise a clamping arrangement for clamping part of the first tool member such that frictional engagement between the first locking arrangement and the first tool member resists translational movement of the first tool member with respect to the second tool member. The tool assembly may comprise a guide arrangement for guiding translational movement of the first tool member with respect to the second tool member. The guide arrangement may be configured to constrain the first tool member to turn with the locking assembly and / or the first locking arrangement and / or the second locking arrangement. The first locking arrangement may comprise the guide arrangement. The locking assembly may comprise a central hub member mounted to the second tool member to turn with respect to the second tool member. The hub member may provide part of the first locking arrangement and / or part of the second locking arrangement. Preferably the hub member provides part of the first and second locking arrangements. The hub member may be mounted to turn in a bore in the second tool member. The hub member may be arranged to turn with respect to the second tool member when the second locking arrangement is in the unlocked configuration. The hub member may be arranged to turn with the first tool member. The hub member may be mounted for limited axial movement with respect to the second tool member. The first tool member may be slidably mounted to the hub member. The first tool member may comprise an elongate slot and a portion of the hub member may extend through the slot to mount the first tool member to the hub member. In this way the first tool member may be retained on the hub member. The hub member may comprise the guide arrangement. The hub member may comprise an engagement portion disposed between the first tool member and the second tool member. The engagement portion may be arranged to engage with the first tool member for resisting translational movement of the first tool member with respect to the second tool member and / or the engagement portion may be arranged to engage with the second tool member (optionally via the frictional element) for resisting pivoting movement of the first tool member with respect to the second tool member. The engagement portion may comprise a first engagement surface for engagement with the first tool member and an opposite second engagement surface for engagement with the second tool member. The first locking arrangement may be arranged to clamp the first tool member against the engagement portion. The first locking arrangement may be arranged to clamp the first tool member against part of the second locking arrangement (which may be provided by the engagement portion). The engagement portion may be arranged to be clamped between the first tool member and the second tool member. The first locking arrangement may be configured to urge the first tool member towards the engagement portion and the second locking arrangement may be configured to urge the second tool member towards the engagement portion. The engagement portion may be substantially disc shaped, or substantially annular. The first locking arrangement may comprise a locking element arranged coaxially with the pivot axis and the locking element may be arranged to engage with the first tool member when the first locking arrangement is in the locked configuration, to resist translational movement of the first tool member. The locking element may be configured to operate the first locking arrangement towards the locked configuration. Movement of the locking element may operate the first locking arrangement towards the locked configuration. The locking element may be arranged to extend around the pivot axis. The locking element may be engaged with the hub member. The locking element may be engaged with the hub member for clamping a portion of the first tool member between the locking element and part of the (engagement portion) of the hub member. The first tool member may be clamped between he locking element and the first engagement surface of the hub member. The locking element may be threadably engaged with the hub member. The locking element may be arranged to move on the hub member in direction parallel to said axis. The locking element may be arranged for limited axial movement on the hub member. The locking element may be engaged with a tubular portion of the hub member. The locking member may be engaged with a threaded outer surface of the hub member. The locking assembly may comprise a locking member which extends along the pivot axis between the first tool member and the second tool member. Movement of the locking member may be configured to operate the second locking arrangement to move the second locking arrangement towards the locked configuration. The locking member may be arranged to secure the locking assembly to the second tool member. The locking element may comprise a recess for receiving part of the locking member. The locking member may be arranged to bear against the hub member to urge the hub member towards the second tool member. The locking element may be arranged to extend (coaxially) around the locking member. The locking member may be arranged to extend coaxially with the locking element. The locking member may be arranged to extend coaxially through (a bore in) the locking element. Axial movement of the locking element on the hub member may be limited by abutment with part of the locking member. The locking member may be arranged to extend through a central bore of the hub member. The second locking arrangement may comprise a bearing member mounted to the second tool member to turn with respect to the second tool member. The bearing member may be engaged with the second tool member for urging the second tool member in a direction parallel to the pivot axis. E.g. towards the first tool member. The locking member may be engageable with the bearing member such that movement of the locking member is arranged to urge the second tool member towards the first tool member. Movement of the locking member may be arranged to urge the second tool member towards the engagement portion of the hub member. The engagement portion of the hub member may be disposed between the first tool member and the bearing member. The bearing member may be coupled to the hub member to turn with the hub member. The bearing member may be mounted for limited axial movement with respect to the second tool member. Part of the second tool member may be clamped between the hub member and the bearing member. The tool assembly may comprise a coupling arrangement for coupling the bearing member to turn with the hub member about the pivot axis. The coupling arrangement may permit relative movement of the hub member and the bearing member in a direction parallel to said axis. An angular position of the first tool member with respect to the second tool member and / or a translational position of the first tool member with respect to the second tool member may be continuously adjustable. In other embodiments, the angular position and / or the translational position may be adjustable to discrete positions. The present invention also provides a handheld tool comprising a tool assembly according to the first aspect of the invention. The present invention also provides a locking assembly for use in the tool assembly of the present invention. The first tool member may comprise a straight edge and the second tool member may comprise a straight edge. The second locking arrangement may be configured to secure an angular position of the straight edge of the first tool member with respect to the straight edge of the second tool member. The first tool member and / or the second tool member may comprise a ruler. Part of the locking assembly may comprise at least one indicator marking for indicating an angle of a straight edge of the first tool member with respect to a straight edge of the second tool member. The at least one indicator marking may be provided on the hub member and / or on the second tool member. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which like reference numerals indicate like features and in which: Figure 1 is a perspective view of a tool assembly according to a first preferred embodiment of the invention; Figure 2 is a plan view of the tool assembly of Figure 1, showing an example of how a first tool member of the tool assembly may be moved pivotally and translationally with respect to a second tool member of the tool assembly; Figure 3 is an upper side perspective exploded view of the tool assembly of Figure 1, showing parts of a locking assembly of the tool assembly for securing relative positions of the first and second tool members; Figure 4 is a lower side perspective exploded view of the tool assembly of Figure 1; Figure 5 is a perspective view of the second tool member of the tool assembly of Figure 1; Figure 6 is a cross-sectional side view of the second tool member shown in Figure 5; Figure 7 is a perspective view of part of the locking of the tool assembly of Figure 1; Figure 8 is a bottom view of the part of the locking assembly shown in Figure 7; Figures 9, 10, and 11 are perspective views of parts of the locking assembly; Figure 12 is a cross-sectional end view of the tool assembly of Figure 1, showing a first locking arrangement of the tool assembly in an unlocked configuration; Figure 13 is a cross-sectional side view of the tool assembly of Figure 1, showing a second locking arrangement of the tool assembly in an unlocked configuration; and Figure 14 is a cross-sectional side view of the tool assembly of Figure 1, showing the second locking arrangement in a locked configuration. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a tool assembly for a handheld tool, in which a relative angular position of parts of the tool, and a relative translational position of the parts of the tool, can be independently adjusted and secured. The present invention is particularly suitable for use as a construction tool for carpentry and the like, for measuring and / or marking angles. In this specification, simply for convenience, the terms “upper”, “upwardly” and related terms are used to refer to a position or direction generally towards the top in Figures 1,34, and 12 to 14, and the terms “lower”, “downwardly” and related terms are used to refer to a position or direction generally towards the bottom in Figures 1, 3, 4 and 12 to 14. It will be appreciated however that the tool assembly may be used in substantially any orientation. A tool assembly 100 according to a first preferred embodiment of the invention is shown in Figures 1,2, 3 and 4. The tool assembly 100 comprises a body 102, and a blade 104. In this embodiment the blade 104 is a first tool member of the tool assembly 100 and the body 102 is a second tool member of the tool assembly 100. The blade 104 is pivotally mounted to the body 102 to pivot about a pivot axis A, so that an angular position of the blade 104 with respect to the body 102 can be adjusted. The blade 104 is also slidably mounted to the body 102 so that a translational position of the blade 104 with respect to the body 102 can be adjusted. Figure 2 shows the tool assembly 100 when an angular position and a translational position of the blade 104 have been changed relative to their respective positions as shown in Figure 1. In the present embodiment the angular and translational positions of the blade 104 with respect to the body 102 are substantially continuously adjustable. Referring to Figures 3 and 4, the tool assembly 100 comprises a locking assembly 106 for securing the angular and translational positions of the blade 104 with respect to the body 102. The locking assembly 106 is arranged to mount the blade 104 to the body 102. In this embodiment, the locking assembly 106 comprises a locking member 108, a locking element 110, a hub member 112, a bearing member 114, and a frictional element 116. The locking assembly 106 provides a first locking arrangement, for securing a translational (sliding) position of the blade 104 with respect to the body 102, and a second locking arrangement for securing an angular position of the blade with respect to the body, as described further below. The blade 104 (which may also be referred to as a ruler) is elongate, having substantially parallel first and second long side edges 118, 120. The side edges 118, 120 are substantially straight. A width of the blade 104 between the side edges 118, 120 is sized to be received in part of the locking assembly 106. The blade 104 is elongate to extend between a first end 122 and a second end 124. A first end edge of the blade 104 extends substantially perpendicular to the length of the blade 104. A second end edge of the blade 104 extends at an angle (preferably 45 degrees) to the length of the blade 104. Upper and lower side surfaces 126, 128 of the blade 104 are substantially planar to extend parallel to a plane of the blade 104, which in this example is substantially perpendicular to the axis A. The blade 104 comprises an elongate slot 130 which extends along the blade 104 and which extends through the blade 104 between the upper and lower side surfaces 126,128. The slot 130 is sized to receive part of the locking assembly 106 to mount the blade 104 for sliding movement relative to the body 102. Referring additionally to Figures 5 and 6, in this embodiment, the body 102 comprises a generally trapezium shaped plate 102, having generally planar upper and lower side surfaces 132, 134. A pair of generally triangular apertures 135 extend through the plate 102 proximate opposite ends of a long side edge of the plate 102. A mounting bore 136 extends through the body 102 between the upper and lower side surfaces 132, 134. The mounting bore 136 extends along the pivot axis A. The mounting bore 136 is sized to receive part of the locking assembly 106, for mounting the locking assembly 106 and the blade 104 to the body 102. As can be seen most clearly in Figure 6, the mounting bore 136 comprises a first, upper portion 138 which extends from the upper side surface 132 towards the lower side surface 134, and a second, lower portion 140 which extends between the upper portion 138 and the lower side surface 134. A diameter of the upper portion 138 is greater than a diameter of the lower portion 140. In this way, an upwardly facing annular surface or seat 142 is provided between the first and second portions 138, 140. An annular retaining groove 144 is provided in the annular seat 142. The annular retaining groove 144 extends around the bore 136. The annular retaining groove 144 is sized to receive and retain the frictional element 116. The upper portion 138 is sized to receive part of the hub member 112. The lower portion 140 of the bore 136 is sized to receive part of the bearing member 114. A diameter of the upper portion 138 is stepped to provide an upper locating region (counterbore) 146 proximate the upper surface 132, and a lower region 148 below the locating region 146. The locating region 146 has a larger diameter than the lower region 148. The locating region 146 extends between the upper surface 132 and the lower region 148. An upwardly facing annular step 150 is thus defined between the locating region 146 and the lower region, proximate the upper surface 132. A diameter of the lower portion 140 of the bore 136 is stepped to provide a lower locating region (counterbore) 152 proximate the lower surface 134 and a bearing region 154 above the lower locating region. The lower locating region 152 has a larger diameter than the bearing region 154. The lower locating region 152 extends between the bearing region 154 and the lower surface 134. A downwardly facing annular step 156 is thus provided between the lower locating region 152 and the bearing region 154, proximate the lower surface 134. Referring also to Figures 7 and 8, the hub member 112 comprises a generally disc shaped engagement portion or clamping portion 158, and a boss portion 160 which protrudes centrally from an upper side 161 of the engagement portion 158. The hub member 112 is arranged to be mounted in the mounting bore 136 in the body 102. In this way the hub member 112 is mounted to turn with respect to the body 102. A diameter of the engagement portion 158 is stepped to provide an upper portion or flange 162 and a reduced-diameter lower portion or mounting portion 164, defining a downwardly facing annular shoulder 166 therebetween. A diameter of the flange 162 is sized to fit in the upper locating region 146 so that the downwardly facing shoulder 166 is arranged to engage with the upwardly facing step 150. A diameter of the mounting portion 164 is sized to be received in the lower region 148 of the upper portion 138 of the mounting bore 136. The engagement portion 158 comprises a pair of diametrically opposed guide members 168 which project upwardly proximate diametrically opposite sides of the engagement portion 158. The guide members 168 are therefore arranged on opposite sides of the boss portion 160. Each guide member 168 comprises a guide edge 170 which is arranged to extend substantially parallel to the guide edge 170 of the opposing guide member 168. A distance between the opposing guide edges 170 is sized to receive a width of the blade 104 with clearance for movement. The boss portion 160 is generally tubular. The boss portion 160 is arranged coaxially with the engagement portion 158. A central bore 172 of the hub member 112 extends through the boss member 160 and centrally through the engagement portion 158. A diameter of the central bore 172 is sized to receive part of the locking member 108. An outer diameter of the boss portion 160 is sized to extend through the slot 130 in the blade 104, for mounting the blade 104 to the hub member 112. The boss portion 160 comprises a threaded outer surface 174 which is arranged to engage with the locking element 110. As can be seen in Figure 8, the hub member 112 comprises a pair of fastener bores 176 which extend into the engagement portion 158 from a lower side 178 of the engagement portion 158. The fastener bores 176 are arranged on opposite sides of the central bore 172. Each fastener bore 176 is internally threaded to engage with part of a corresponding fastener 180 for mounting the hub member 112 to the body 102, as described further below. The hub member 112 further comprises a pair of blind upper guide bores 182 which open on the lower side 178 of the engagement portion 158. The upper guide bores 182 are arranged on opposite sides of the central bore 172, angularly offset from the fastener bores 176. The upper guide bores 182 are each sized to receive part of a respective guide pin 184, for guiding axial movement of the hub member 112 with respect to the body 102 and the bearing member 114. Referring also to Figure 9, in this embodiment the locking element 110 comprises a generally annular body 110 through which extends an internally threaded central bore 186. The threaded central bore 186 is sized to receive and engage the externally threaded boss portion 160 of the hub member 112. In this way the locking element 110 is arranged to turn on the boss portion 160 and to move axially on the boss portion 160. An outer circumferential surface of the locking element 110 is provided with grip formations or knurling 188 to help a user to turn the locking element 110. Figure 10 shows the locking member 108, which in this embodiment comprises an elongate fastener member 108 comprising a head 190 and a threaded shank 192. The head 190 is arranged to engage with an end of the boss portion 160. The head 190 comprises a gripping element 194 projecting from an opposite side of the head 190 to the shank 192, for helping a user of the tool assembly to turn the locking member 108. A diameter of the shank 192 is sized to fit with clearance in the central bore 172 of the hub member 112. The shank 192 is arranged to extend through the central bore 172 for engagement with the bearing member 114. A distal end portion of the shank 192 furthest from the head 190 is arranged to engage with the bearing member 114. Turning to Figure 11, the bearing member or plug member 114 comprises a generally cylindrical body 114 having a generally cylindrical bearing portion 196 and an annular retaining lip 198 which projects radially at an end of the bearing portion 196. The lip 198 has a larger diameter than the bearing portion 196. An internally threaded central bore 200 extends coaxially into the bearing portion 196 from a first, upper end 202 of the bearing portion 196 furthest from the lip 198. The threads of the central bore 200 are arranged to engage with the threaded shank 192. The bearing member 114 comprises a pair of fastener holes 204 which pass through the bearing member 114 on either side of the central bore 200. Each fastener hole 204 is arranged to receive part of one of the fasteners 180 for securing the bearing member 114 to the hub member 112. Each fastener hole 204 is sized to receive a respective fastener 180 with clearance to allow the fastener 180 to move axially in the hole 204. The bearing member 114 further comprises a pair of blind lower guide bores 206 which extend into the bearing portion 196 from the upper end 202 of the bearing portion 196. Each lower guide bore 206 is arranged to receive part of a respective one of the guide pins 184. Figures 12, 13 and 14 show the arrangement of the parts described above, in the assembled tool assembly 100. The blade 104 is mounted to the body 102 by the locking assembly 106, to permit or resist relative movement of the blade 104 and the body 102, as will now be described. The hub member 112 is mounted to the body 102 by locating part of the hub member 112 in the mounting bore 136. In particular the mounting portion 164 is received in the lower region 148 of the upper portion 138. The flange 162 is received in the upper locating region 146 such that the downwardly facing annular shoulder 166 is arranged to engage with the upwardly facing annular step 150. The shoulder 166 may be spaced apart from the step 150 or engaged with step 150 in different configurations of the locking assembly 106, as described further below. The bearing member 114 is received in the lower portion 140 of the mounting bore 136. In particular, the bearing portion 196 is received in the bearing region 154 of the mounting bore 136 and the lip 198 is received in the lower locating region 152. In this way an upwardly facing annular surface of the lip 198 is arranged to engage with the downwardly facing annular step 156, to block upward movement of the bearing member 114 with respect to the body 102. The bearing member 114 is arranged to turn in the lower portion 140 of the mounting bore 136. With reference to Figure 12, to retain the hub member 112 with respect to the body 102, the hub member 112 is secured to the bearing member 114 by the fasteners 180 (which in this embodiment are screws). The fasteners 180 extend through the oversized fastener holes 204 in the bearing member 114 and are threadably engaged with the fastener bores 176 in the hub member 112. Heads of the fasteners 180 are arranged to engage with the bearing member 114 to limit movement of the bearing member 114 away from the hub member 112. Since the fastener holes 204 are sized with clearance for shafts of the fasteners 180, the bearing member 114 is arranged for limited axial movement (e.g., along the pivot axis) with respect to the hub member 112. As can be seen in Figures 13 and 14, the guide pins 184 are received with clearance in the upper and lower guide bores 182, 206, to guide the relative axial movement of the hub 112 and bearing member 114. The guide pins 184 and fasteners 180 together transmit turning forces between the hub 112 member and bearing member 114. In this way, the locking assembly 106 comprises a coupling arrangement for coupling the bearing member 114 to turn with the hub member 112. With the hub member 112 mounted in the bore 136, a lower surface 208 of the engagement portion 158 of the hub 112 faces the annular seat 142. The frictional element 116 (which in this embodiment is a resiliently deformable O-ring 116) is retained in the retaining groove 144. The frictional element 116 is therefore arranged to engage with the lower surface 208 of the engagement portion 158. The frictional element 116 is arranged to be clamped between the body 102 and the hub member 112, as described further below. The locking element 110 is mounted on the boss portion 160. The locking element 110 is threadably engaged with the external threads of the boss portion 160 so that turning of the locking element 110 with respect to the hub member 112 causes the locking element 110 to move along the boss portion 160 towards or away from the engagement portion 158. The blade 104 is mounted to the hub member 112. In particular, the blade 104 is disposed between the guide members 168 and is slidably engaged with the guide members 168. The boss portion 160 extends through the slot 130. The lower surface 128 of the blade 104 is slidably engaged with the surface of the upper side 161 of the engagement portion 158 between the guide members 168. In this way the blade 104 may slide with respect to the hub member 112 by sliding of the blade 104 between the guide members 168, with relative sliding of the boss portion 160 in the slot 130. With this arrangement the blade 104 is arranged to slide in a plane substantially perpendicular to the axis A. The blade 104 is constrained to turn with the hub member 112 by the guide members, which block turning of the blade 104 about the axis A with respect to the hub member 112. With this arrangement therefore, forces acting to pivot the blade 104 with respect to the body 102 act to turn the hub member 112 with respect to the body 102. As can be seen in Figures 12 to 14, the blade 104 is disposed between the engagement portion 158 and the locking element 110. The locking element 110 may therefore be used to secure a translational (sliding) position of the blade 104 with respect to the hub member 112 (and thus with respect to the body 102). Turning of the locking element 110 in first direction moves the locking element 110 towards the engagement portion 158, to clamp a portion of the blade 104 between the locking element 110 and the engagement portion 158. Turning of the locking element 110 in an opposite, second direction releases the blade 104 to allow the blade 104 to slide with respect to the hub member 112. With these arrangements the locking assembly 106 comprises a first locking arrangement for releasably securing a translational position of the blade 104 with respect to the body 102. The first locking arrangement is therefore operable between a first, unlocked configuration in which the blade 104 is not clamped between the locking element 110 and the engagement portion 158 and so is free to slide, and a second, locked configuration in which the blade 104 is clamped between the locking element 110 and the engagement portion 158 to resist sliding of the blade 104. Figure 12 shows the first locking arrangement in the unlocked configuration and Figures 13 and 14 show the first locking arrangement in the locked configuration. The shank 192 of the locking member 108 extends through the central bore 172 of the hub member 112 and the distal end portion of the shank is threadably engaged with the threaded bore 200 of the bearing member 114. The head 190 is arranged to locate in a recess or counterbore 185 provided in an upper end of the locking element 110, (as can also be seen referring back to Figure 3). The head 190 is arranged to bear against an upper end 165 of the boss portion 160. With this arrangement, turning of the locking member 108 in a first direction urges the bearing member 114 towards the hub member 112. Since movement of the bearing member 114 towards the hub member 112 is blocked by abutment of the lip 198 with the downwardly facing annular step 156, tension is generated in the shank 192, which causes the head 190 to bear against the end 165 of the boss portion 160. In this way, the hub member is urged towards the seat 142 and the O-ring 116 is clamped between the engagement portion 158 and the body 102, as can be seen in Figure 7. With this arrangement, frictional engagement between the hub member 112 and the frictional element 116 acts to resist pivoting of the hub member 112 with respect to the body 102. Since the blade 104 is coupled to turn with the hub member 112, pivoting of the blade 104 with respect to the body 102 is therefore resisted. Turning of the locking member 108 in an opposite direction reduces the force with which the head 190 bears against the boss portion 160, allowing the hub member 12 to move away from the seat 142, as can be seen in Figure 13. The resiliently deformable O-ring 116 provides a biasing force to urge the hub member 112 away from the seat 142. A clearance gap 205 may open between the lower surface 208 of the engagement portion 158 and the seat 142. As the hub member 112 moves away from the seat 142, frictional engagement between the O-ring 116 and engagement portion 158 is reduced, such that the hub 112 may be pivoted with respect to the body 102, and thus the blade 104 may be pivoted to adjust an angular position of the blade 104 with respect to the body 102. With these arrangements, the locking assembly 106 comprises a second locking arrangement for releasably securing an angular position of the blade 104 with respect to the body 102. The second locking arrangement is operable between a first, unlocked configuration in which the blade 104 may be pivoted about the axis A with respect to the body 102 (shown in Figure 13), and a second, locked configuration in which the angular position of the blade 104 with respect to the body 102 is secured (shown in Figure 14). It will be appreciated that, with the arrangements described above, the first and second locking arrangements may be operated independently of one another. Also, because the first locking arrangement (comprising the locking element 110) is arranged to turn with the blade 104, pivoting of the blade 104 with respect to the body 102 does not result in unwanted operation (e.g., locking or unlocking) of the first locking arrangement, because the blade 104 cannot act to turn the locking element 110 on the boss 160 to tighten or loosen the locking element 110. It will also be appreciated that the locking member 108, in addition to the fasteners 180, helps to secure the hub member 112 and bearing member 114 to the body 102 by abutment of the boss portion 160 with the head 190. Moreover, a diameter of the head 190 is larger than an outer diameter of the boss portion 160, such that upward movement of the locking element 110 away from the body 102 is blocked by the head 190. In this way the locking member helps to retain the locking element 110 on the boss portion 160. In preferred embodiments, the tool assembly may comprise indicator markings (not shown) for reading an angle between a straight edge of the blade and a straight edge of the body. For example, markings may be provided on an upper surface of the hub member, to be read against corresponding markings provided on the upper surface of the body around the mounting bore. Although in the embodiments described above the frictional element is mounted to the body, in other embodiments, a frictional element may be disposed in any suitable position to provide friction to resist pivoting of the hub member. For example, a frictional element may (additionally or alternatively) be mounted to the hub. A frictional element may be disposed between the bearing member and the body. In some embodiments, the hub member and / or the blade may be provided with bearing elements (such as rolling elements) for movement of the blade with respect to the hub member. In some embodiments, the frictional element may be absent, and frictional engagement between the engagement portion and the seat may be sufficient to resist pivoting of the blade. Additionally or alternatively, in some examples, the locking assembly may comprise means for securing the blade at discrete angles with respect to the body. With such arrangements the locking assembly may be configured to set the blade such that an edge of the blade extends at a desired angle (e.g., 30, 45, 60 or 90 degrees) to an edge of the body. For example, the locking assembly may comprise complementary inter-engaging elements such as intermeshing teeth. For instance, teeth provided on the body or hub member may be arranged to engage with complementary teeth provided on the hub member, or blade, respectively. In some embodiments, the locking assembly or the body may comprise a follower such as a ball plunger which is arranged to engage with a track provided on the other of the locking assembly and the body, to resist movement of the blade with respect to the body. The track may comprise one or more detent formations to detain progress of the ball along the track for setting the blade at one or more discrete angles with respect to the body. In some embodiments, biasing means may be provided to maintain a degree of frictional engagement of the hub member with the body when the second locking arrangement is in an unlocked configuration and / to maintain a degree of frictional engagement with the blade when the first locking arrangement is in an unlocked configuration. In this way, unwanted slipping or pivoting of the blade (for example 5 due to gravity) may be avoided whilst a position of the blade is being adjusted. For example a resilient member may be arranged to urge the blade and body towards one another. With the arrangements described above, the present invention provides convenient, 10 reliable and compact means to secure the relative position of parts a handheld tool. Further modifications and variations not explicitly described above are also possible without departing from the scope of the invention as defined in the appended claims.

Claims

1. A tool assembly for a handheld tool, the tool assembly comprising:a first tool member; anda second tool member;wherein the first tool member is mounted to pivot with respect to the second tool member about a pivot axis for adjusting an angular position of the first tool member with respect to the second tool member; andwherein the first tool member is mounted for translational movement with respect to the second tool member, for adjusting a translational position of the first tool member with respect to the second tool member;the tool assembly further comprising a locking assembly comprising:a first locking arrangement for securing the translational position of the first tool member with respect to the second tool member, the first locking arrangement being operable between an unlocked configuration in which the first tool member may translate with respect to the second tool member, and a locked configuration in which the translational position of the first tool member with respect to the second tool member is secured; anda second locking arrangement for securing the angular position of the first tool member with respect to the second tool member, the second locking arrangement being operable between an unlocked configuration in which the first tool member may be pivoted about said axis with respect to the second tool member, and a locked configuration in which the angular position of the first tool member with respect to the second tool member is secured;wherein, with the second locking arrangement in the unlocked configuration, the first locking arrangement is arranged to turn with the first tool member, with respect to the second tool member; andwherein the first locking arrangement is operable independently of the second locking arrangement.

2. A tool assembly according to Claim 1, in which the locking assembly is configured to mount the first tool member to the second tool member.

3. A tool assembly according to Claim 1 or Claim 2, in which the first locking arrangement and the second locking arrangement are arranged coaxially with the pivot axis.

4. A tool assembly according to any preceding claim, in which the second locking arrangement is configured, in the locked configuration, to urge the second tool member against part of the second locking arrangement such that frictional engagement between the second locking arrangement and the second tool member resists pivoting of the first tool member with respect to the second tool member.

5. A tool assembly according to any preceding claim, comprising a frictional element arranged to be clamped between the second locking arrangement and the second tool member to provide a frictional force between the second locking arrangement and the second tool member.

6. A tool assembly according to Claim 4 or Claim 5, in which the frictional element is engaged with the second locking arrangement and with the second tool member when the second locking arrangement is in the locked configuration and when the second locking arrangement is in the unlocked configuration.

7. A tool assembly according to Claim 5 or Claim 6, in which the frictional element comprises a resiliently deformable element.

8. A tool assembly according to any preceding claim, in which the first locking arrangement comprises a clamping arrangement for clamping part of the first tool member such that frictional engagement between the first locking arrangement and the first tool member resists translational movement of the first tool member with respect to the second tool member.

9. A tool assembly according to any preceding claim, comprising a guide arrangement for guiding translational movement of the first tool member with respectto the second tool member, wherein the guide arrangement is configured to constrain the first tool member to turn with the locking assembly.

10. A tool assembly according to any preceding claim, in which the locking assembly comprises a central hub member mounted to the second tool member to turn with respect to the second tool member, wherein the hub member provides part of the first locking arrangement and part of the second locking arrangement.

11. A tool assembly according to Claim 10, in which the hub member is mounted for limited axial movement with respect to the second tool member.

12. A tool assembly according to Claim 10 or Claim 11, in which the first tool member is slidably mounted to the hub member.

13. A tool assembly according to any of Claims 10 to 12 when dependent on Claim 9, in which the hub member comprises the guide arrangement.

14. A tool assembly according to any of Claims 10 to 13, in which the hub member comprises an engagement portion disposed between the first tool member and the second tool member, the engagement portion being arranged to engage with the first tool member for resisting translational movement of the first tool member with respect to the second tool member and the engagement portion being arranged to engage with the second tool member for resisting pivoting movement of the first tool member with respect to the second tool member.

15. A tool assembly according to Claim 14, in which the first locking arrangement is configured to urge the first tool member towards the engagement portion and the second locking arrangement is configured to urge the second tool member towards the engagement portion.

16. A tool assembly according to any preceding claim, in which the first locking arrangement comprises a locking element arranged coaxially with the pivot axis andthe locking element is arranged to engage with the first tool member when the first locking arrangement is in the locked configuration, to resist translational movement of the first tool member.

17. A tool assembly according to Claim 16 when dependent on any of Claims 10 to 15, in which the locking element is engaged with the hub member for clamping a portion of the first tool member between the locking element and part of the hub member.

18. A tool assembly according to Claim 17, in which the locking element is threadably engaged with the hub member.

19. A tool assembly according to any preceding claim, in which the locking assembly comprises a locking member which extends along the pivot axis between the first tool member and the second tool member and wherein movement of the locking member is configured to operate the second locking arrangement to move the second locking arrangement towards the locked configuration.

20. A tool assembly according to Claim 19 when dependent on any of Claims 16 to 18, in which the locking element is arranged to extend around the locking member.

21. A tool assembly according to any of Claims 11 to 20 when dependent on Claim 10, in which the locking member is arranged to extend through a central bore of the hub member.

22. A tool assembly according to any preceding claim, in which the second locking arrangement comprises a bearing member mounted to the second tool member to turn with respect to the second tool member, and wherein the bearing member is engaged with the second tool member for urging the second tool member in a direction parallel to the pivot axis.

23. A tool assembly according to Claim 22 when dependent on any of Claims 19 to 21, in which the locking member is engageable with the bearing member such that movement of the locking member is arranged to urge the second tool member towards the first tool member.

524. A tool assembly according to Claim 22 or Claim 23 when dependent on Claim 14 or any claim dependent on Claim 14, in which the engagement portion of the hub is disposed between the first tool member and the bearing member.10 25. A tool assembly according to any of Claims 22 to 24 when dependent onClaim 10 or any claim dependent on Claim 10, comprising a coupling arrangement for coupling the bearing member to turn with the hub member about the pivot axis, and wherein the coupling arrangement permits relative movement of the hub member and the bearing member in a direction parallel to said axis.15

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