TECHNICAL FIELD

[0001] This disclosure relates generally to apparatus for finishing workpieces by processes such as, for example, polishing, linishing, grinding or the like.

BACKGROUND ART

[0002] One type of apparatus to which the disclosure relates is referred to as a linishing apparatus which comprises an assembly which includes an arrangement of wheels, pulleys or rollers (which will be hereinafter be generally referred to as wheels) around which an endless belt extends or is entrained. The linishing belt has a treatment surface thereon, such as for example an abrasive, against which the workpiece is applied to achieve the desired result. One of the wheels comprises a drive wheel powered by a motor causing rotation thereof. The apparatus further comprises at least one other wheel in the form of an idler wheel the belt moving around the wheels when driven. Such apparatus can be used for finishing objects such as tools, building materials or the like. The apparatus can be used for example to provide a flat level surface to a workpiece or for finishing an edge of the workpiece.

[0003] Known apparatus of this type have several problems. In particular, changing the belt can be difficult and in some cases dangerous for the operator. In addition, it is not possible to change the belt orientation to allow a variety of work positions.

SUMMARY OF DISCLOSURE

[0004] In a first aspect, embodiments are disclosed of apparatus for installation to a base structure and for use in finishing a workpiece, the apparatus comprising a main body which includes a mounting section, and an idler wheel support having an idler wheel operatively mounted thereon, the idler wheel being configured for use with a drive wheel, the wheels together being configured to carry an endless belt which extends or is entrained therearound, the main body, when in an installed position, is attached to the base structure, the idler wheel support being mounted to the mounting section so that the idler wheel is spaced from the mounting section.

[0005] In certain embodiments, the idler wheel support is pivotally mounted to the mounting section for pivotal movement about a pivot axis so that the idler wheel support can adopt a plurality of different working positions, the apparatus including a releasable locking arrangement operable to lock the idler wheel support in at least some of the working positions. [0006] In certain embodiments, the drive wheel is rotatable about a rotation axis which is coaxial with the pivot axis. In certain embodiments, the base structure houses a motor having a driveshaft rotatable about a driveshaft axis, such that when the apparatus is installed, the pivot axis, rotation axis and driveshaft axis are coaxial.

[0007] In certain embodiments, the locking arrangement comprises a cooperating toothed section and a detent, the detent being movable between a locked position, in which pivotal movement of the idler wheel support is inhibited, and a release position, in which the idler wheel support is pivotable about the pivot axis.

[0008] In certain embodiments, the toothed section has a curved profile on a part of the main body and the detent comprises a member having teeth arranged in a complementary configured curved profile and configured to be in meshing engagement with the toothed section when in the locked position.

[0009] In certain embodiments, the main body includes an end section secured to the mounting section so as to form a rigid structure, the mounting section being attached to the base structure when in the installed position so that the end section is disposed adjacent the base structure with the mounting section being disposed inwardly from the end section away from the base structure.

[0010] In certain embodiments, the end section comprises an end member having a peripheral edge which is at least in part curved, the toothed section of the locking arrangement being on the curved part of the peripheral edge.

[0011] In certain embodiments, the end member comprises a generally ring-shaped plate.

[0012] In certain embodiments, the detent comprises an elongated element pivotally mounted to the idler wheel support for movement between the locked and released positions about a pivot point, the element further comprising a manually operable activating lever.

[0013] In certain embodiments, the mounting section comprises a circular disc shaped member having an outer peripheral edge, the idler wheel support comprising an elongated body having a support mount in the region of one end thereof and having a hole therein, the hole being sized and configured to overlie the outer peripheral edge of the disc shaped member so as to provide for cooperating bearing surfaces enabling the support to be rotated about the disc shaped member. In certain embodiments, the outer peripheral edge of the disk shaped member is disposed radially inwardly from the peripheral edge of the end member.

[0014] In certain embodiments, the support mount includes a mounting plate, the hole being located within the mounting plate, the support mount further including a flange extending laterally from the plate, the idler wheel support further including an arm assembly comprising a first arm section and a second arm section each having a longitudinal axis, the second arm section being slidably receivable within the first arm section for relative movement in the axial direction between an extended position and a retracted position.

[0015] In certain embodiments, the apparatus further includes a control arrangement for controlling the relative movement of the first arm section and the second arm section between the extended and retracted positions. The control arrangement includes a control member and a spring operatively arranged so as to act on the control member, the spring being configured so as to urge the arm sections into the extended position.

[0016] In certain embodiments, the control arrangement is such that an initial relative axial movement of the arm sections towards one another into the retracted position causes the control member to be held with the arm sections in the retracted position and a further axial movement towards one another causes the control member to be released so that the arm sections can return to the extended position under the influence of the spring.

[0017] In certain embodiments, the control member includes a recessed section in a surface thereof, the recessed section having a profiled edge and a stop, the profiled edge and stop providing pathways, the recess section being adapted to receive a tracking pin lug therein which can travel along the pathways so as to engage and disengage from the stop so as to cause the control member to adopt its held or release positions.

[0018] In certain embodiments, the apparatus further includes a guard which can be releasably fitted so that in a fitted position it overlies the drive wheel.

[0019] In certain embodiments, the guard is releasably securable to the support mount of the idler wheel support by cooperating apertures and fasteners, the apertures comprising an enlarged end and a smaller end, the fasteners comprising a head and a shank, the head of the fasteners being sized so that it can pass through the enlarged end of the aperture but not through the smaller end. [0020] In certain embodiments, the apparatus further includes a work platform operatively mounted for movement between an in use position and a non-use position.

[0021] In certain embodiments, the apparatus further includes a mounting assembly for mounting the work platform to the arm assembly of the idler wheel support so as to enable rotation of the work platform between the in use and non-use positions.

BRIEF DESCRIPTION OF DRAWINGS

[0022] Notwithstanding any other forms which may fall within the scope of the method and apparatus set forth in the summary, specific embodiments of the method and apparatus will now be described by way of example and with reference to the accompanying drawings in which:

[0023] Figure 1 is an isometric view of the apparatus according to one embodiment from one side;

[0024] Figure 2 is an isometric view of the apparatus shown in Figure 1 from the other side;

[0025] Figure 3 is a similar view of the apparatus as shown in Figure 1 with some components removed;

[0026] Figure 4 is an isometric view of part of the apparatus shown in figures 1 to 3;

[0027] Figure 5 to 8 are detailed illustrations of that part of the apparatus shown in figure 4;

[0028] Figure 9 is a schematic illustration of an example of an installation which includes apparatus according to one embodiment;

[0029] Figure 10 is a schematic illustration of one example of a locking arrangement utilised the apparatus of figure 1; and

[0030] Figure 11 is an exploded view of the apparatus according to one embodiment.

DETAILED DESCRIPTION

[0031] Referring to the drawings, there is shown apparatus generally indicated at 10 comprising a main body 12. When installed, the main body 12 can be mounted to a base structure which is adapted to support the apparatus 10. An example of a base structure with which the apparatus 10 can be used is illustrated in figure 9. The structure 100 comprises a housing 102 for a motor. A grinding wheel 104 is mounted at one end of the housing 102 and the apparatus 10 is mounted at the other end. Two drive shafts (not shown) are provided, one for the grinding wheel 104 and the other for the apparatus 10. The apparatus 10 further includes a drive wheel or pulley 30 (figures 2 and 3) which, when installed, is operatively secured to the driveshaft so that rotation of the driveshaft causes rotation of the drive wheel 30 about a rotation axis X-X (figure 3).

[0032] In the embodiment shown, the main body includes an end section 14 which comprises an end member 15 in the form of a ring-shaped plate 16 having an outer peripheral edge 17. End member 15 is disposed adjacent to the base structure 100 when installed. The apparatus 10 further includes a mounting section 18 which is disposed inwardly and adjacent to the end section 14.

[0033] As best illustrated in figure 3, the mounting section 18 is in the form of a disc shaped member 20 generally circular in shape and has a circumferential edge 19, the purpose of which will become hereinafter apparent. The circumferential edge 19 is inwardly spaced in a generally radial direction from the outer peripheral edge 17 of the ring shaped plate 16. It can be seen that the two components 16 and 18 together form a rigid assembly structure which can be secured to the base structure 100. In the embodiment shown the mounting section 18 is secured to the base structure 100 and plate 16 is secured to mounting section 18.

[0034] As referred to earlier, the apparatus 10 further includes a drive wheel 30 which is arranged to be operatively mounted to a drive shaft for rotation about a rotation axis X-X. The wheel 30 includes a central bore 31 for receiving the drive shaft. The drive shaft extends from the base structure through apertures 13 and 23 in members 16 and 20 and is operatively secured within the bore 31. The drive wheel 30 may include an end plate 32 to which an abrasive pad cover can be fitted. The apparatus 10 further includes an idler wheel 34 arranged so that an endless belt (not shown) can be entrained around the wheels 30 and 34. The idler wheel 34 is operatively mounted to an idler wheel support 36, which is operatively mounted to the mounting section 18. The belt may be used in a finishing operation on a work piece such as polishing or flattening a surface on the work piece.

[0035] The structure of the idler wheel support 36 is best understood by reference to figures 4 to 8. The idler wheel support 36 comprises an elongated body 37 having a support mount 35 at one end with the idler wheel or pulley 34 at the other end. The support mount 35 comprises a mounting plate 33 having a hole 38 therein sized so that its circumferential edge 41 abuts against the circumferential edge 19 of the member 20. Thus, the edges form bearing surfaces by which the support mount 35 can pivot or rotate about a pivot axis Y-Y. The elongated body 37 comprises an arm assembly 48 on one end that is secured to a flange 46, which forms part of the support mount 35. As shown, pivot axis Y-Y is co-axial with rotation axis X-X.

[0036] The apparatus 10 further includes a locking arrangement 40 by which the idler wheel support 36 can be locked in a selected operative position. The locking arrangement 40 comprises a toothed section 42 on the outer edge 17 of the ring-shaped plate 16 which is adapted to cooperate with a detent 44 on the idler wheel support 36. The detent 44 includes a curved edge 39 having a series of teeth 45 thereon which can releasably engage with the teeth 42 on the ring shaped member 16, in a meshing position. The detent 44 is pivotally mounted and includes a manually operable activating lever 47 for pivotally moving the detent teeth 45 out of engagement with the toothed section 42. A releasable lock member 49 is operable to lock the detent 44 into engagement with the toothed section 42. An example embodiment of lock member 49 is illustrated in figure 10. As shown the lock member 49 includes an actuating knob 105 having a threaded shaft 106 which can be screwed into mounting plate 33 to which lever 47 is pivotally mounted. The lock member 49 further includes a frustoconical locating section 107 which is adapted to cooperate with an aperture 108 in the lever 47. The aperture 108 is sized so that locating section 107 can be positioned therein. By rotation of the knob 105 the locating section 107 can be caused to enter the aperture 108. When disposed within the aperture 108, the lever 47 is caused to pivot, urging the teeth 45 into engagement with toothed section 42 thereby locking the two parts together. Rotating the knob 105 in the opposite direction causes the locating section 107 to move out of the aperture 108 and allows pivotal movement of the lever 47 so that the teeth 42 and 45 can be disengaged. Typically, when the locating section 107 is disengaged from the aperture 108, the lever pivots due to gravity such that teeth 42 and 45 disengage.

[0037] The arm assembly 48 comprises first and second arm sections 61 and 62. The first and second arm sections 61 and 62 are arranged for movement relative to one another in an axial direction between an extended position and a retracted position. When in the extended position, the belt is in its operative mode and is held in a taught or tensioned state. When in the retracted position, the overall length of the arm assembly is shortened thereby enabling the belt to be readily removed from the wheels 30 and 34. The first arm section 61 is generally tubular in form and is secured at one end to flange 46. The first arm section 61 has an internal cavity 63 therein which has a circular contour when viewed in cross section. The second arm section 62 is at least partially slidably receivable within the first arm section 61 and has an outer peripheral side 64 which has a circular contour when viewed in cross section which is sized so that the side 64 is adjacent to the inside surface of the cavity 63. The idler wheel 34 is mounted to an outer end of the second arm section 62.

[0038] The apparatus further includes a control arrangement 80 which is adapted to control the relative movement of the first and second arm sections, 61 and 62, between the extended and retracted positions. The control arrangement 80 comprises a housing 81 which is sized so as to be receivable within the cavity 63 of the first arm section 61. The housing 81 has a bore 83 therein which extends from an open end 84 towards the other end of the housing 81. The bore 83 has a generally D-shaped contour when viewed in cross-section having a substantially flat or straight side 65, a curved side 66 and connecting sides 67. A spring 85 is arranged to be mounted within the bore 83.

[0039] A control member 86 is arranged so that it can be disposed at least partially within the bore 83 and configured so as to be responsive to forces generated by the spring 85. The control member 86 has a cross-sectional shape which is complementary to that of the bore 83 and includes a side 75 having a substantially flat surface 76, a curved side 77 and connecting sides 78. The side 75 has a recessed section 87 in the side surface 76, the recessed section 87 having an outer profiled edge 88 and a stop 89. The outer edge 88 and stop 89 provide for guide pathways 97 and 98 the purpose of which will hereinafter be explained. A tracking pin 90 is operatively mounted to the housing 81. The tracking pin 90 includes a head 91 which can be mounted to a post 93 on the housing so as to be pivotal thereon. The pin 90 includes a leg 95 extending from the head, and a tracking lug or projection 96 extending laterally from the leg 95 and arranged to be positioned within the recessed section 87. The post is disposed within a recess 92 in the side of the housing 81 and adjacent an aperture 94 which extends through the side thereof.

[0040] In the extended position of the arms 61 and 62, the spring 85 acts on the control member 86 which in turn acts on arm 62 to push it outwardly away from arm 61. This action is shown by arrow B in figure 8. In this position the belt is held taught or tensioned for use in a finishing operation. When the belt is required to be replaced for example, the arm 62 is pushed inwardly along the internal cavity 63 in the first arm section 61 against the control member 86 and the force of the spring 85. This action is shown by arrow A in figure 8. As a result of this movement the spring 85 is compressed and the tracking lug 96 of pin 90 travels along pathway 97. When it reaches the end of the recess beyond the stop 89, release of the arm 62 will cause the lug 96 to be urged into abutment against the stop 89, thereby holding the arm 62 in the retracted position. This is best seen in figure 8. The stop 89 is V-shaped with one arm longer than the other. This ensures that the lug 96 will engage the stop 89 when the arm 62 is released. To release the lug 96, the arm is pushed in the direction of arrow A thereby enabling the lug 96 to clear the stop 89 and return along pathway 98 under the influence of the spring 85.

[0041] A holding mechanism 51 is arranged to inhibit over extension of the arm assembly 48. That is, it inhibits the arm assembly 48 from coming apart under the influence of the spring 85. The holding mechanism 51 comprises an elongated member 58 which is operatively secured to the second arm section 62 and has an elongated slot 59 therein. The mechanism 51 further includes a cooperating flange 68 on arm section 61 , the flange 68 having a guide pin 69 associated therewith. The guide pin 69 is received in the slot 59 thereby limiting axial movement between the arm sections 61 and 62. The guide pin 69 may be configured so that it can be locked at any position along the slot 59. The guide pin 69 is also associated with a second flange 79 on the other end to prevent it from leaving the elongated slot 59, as shown in figure 4.

[0042] The apparatus further includes a guard 70 which, when fitted, overlies the drive wheel 30. The guard 70 is releasably secured to the support mount 35 by fasteners 72 having a shank and a head arranged to cooperate with keyhole shaped apertures 71 having an enlarged end 73 and a small end 74. The head of the fasteners 72 is adapted to pass through the enlarged end 73 of the apertures 71 and thereafter the guard 70 is manipulated into a position where the shank of the fastener 72 extends through the smaller end 74 of the aperture 71 and the head of the fastener 72 is sized so that it is larger than the smaller end 74, thereby inhibiting release of the fastener 72 from the aperture 71. The manipulation of the guard 70, as described above, enables the guard 70 to be released or fitted without requiring dismantlement of any of the other components of the apparatus. To facilitate mounting of the guard 70, a bent handling lip 99 extends from an end portion thereof (typically, a top portion of the guard 70). In other embodiments, an additional bent lip 99 may also be provided at the opposite end portion of the guard 70, such that the guard 70 may be easily mounted/manipulated when the apparatus 10 is secured to an opposite side of base structure 100 (i.e. the guard 70 may be easily mounted whether the apparatus 10 is mounted to either a right side or a left side of an appropriate base structure 100).

[0043] The apparatus further includes a work platform 50 operatively mounted for movement between an in use position and a non-use position. The work platform 50 comprises a table 57 and a mounting assembly 52 which operably mounts the table 57 to the arm assembly 48. The arrangement is such that the table 57 can be rotated about the arm assembly 48 between the in use position as shown in the drawings and a non-use position. In the in use position, the table 57 is positioned above the arm assembly 48. In this position it is disposed adjacent and below the belt. In the non-use position the table 57 is rotated about the axis of the arm assembly 48 so as to be positioned to one side thereof. The mounting assembly 52 comprises a bracket 53 including a cylindrical section 54 which surrounds the arm assembly 48 and is rotatable relative thereto. A guide 55 which comprises a flange 56 on the arm assembly 48 has a slot therein which receives a guide pin (not shown) extending from the bracket 53. The guide 55 thus restricting rotation of the work platform 50. A side table 60 may be optionally provided, the side table 60 operatively secured to the structure 100 or main body 12. The side table 60 can provide a further work platform and can be mounted for pivotal movement between an outwardly extremely operative position and a non-use orientation.

[0044] The apparatus further includes a belt tracking adjustment arrangement 110 manually operable by knob 111. The arrangement 110 is disposed in the region of the idler wheel 34.

[0045] It will be appreciated that in alternate forms, the apparatus may be provided in combination with the base structure as single assembly, as opposed to being releasably installable/mountable thereto.

[0046] In the forgoing description of preferred embodiments, specific terminology has been resorted to for the sale of clarity. However, the invention is not intended to be limited to specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as “front” and “rear”, “inner” and “outer”, “above”, “below”, “upper” and lower” and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

[0047] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as, an acknowledgement or admission or any form of suggestions that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

[0048] In this specification the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of”. A corresponding meaning is to be attributed to the corresponding words “comprise”, “comprised” and “comprises” where they appear. [0049] The reference numerals in the following claims do not in any way limit the scope of the respective claims.

TABLE OF PARTS

Apparatus 10 Activating lever 47

Main body 12 Arm assembly 48

Aperture 13 Releasable lock member 49

End section 14 Work platform 50

End member 15 Holding Mechanism 51

Ring shaped plate 16 Mounting Assembly 52

Outer peripheral edge 17 Bracket 53

Mounting section 18 Cylindrical Section 54

Circumferential edge 19 Guide 55

Disc shaped member 20 Flange 56

Aperture 23 Table 57

Drive wheel 30 Elongated Member 58

Bore 31 Elongated Slot 59

End plate 32 Side Table 60

Mounting plate 33 First arm section 61

Idler wheel 34 Second arm section 62

Support mount 35 Cavity 63

Idler wheel support 36 Outer peripheral side 64

Elongated body 37 Straight upper side 65

Hole 38 Curved lower side. 66

Curved edge 39 Connecting sides 67

Locking arrangement 40 Cooperating Flange 68

Circumferential edge 41 Guide Pin 69

Toothed section 42 Guard 70

Detent 44 Key apertures 71

T eeth 45 Fasteners 72

Flange 46 Enlarged End 73 Small End 74 Leg 95

Side 75 Tracking lug or projection 96

Flat surface 76 Guide pathway 97

Side 77 Guide pathway 98

Connecting sides 78 Bent Handling Lip 99

Second Flange 79 Structure 100

Control arrangement. 80 Housing 102

Housing 81 Grinding wheel 104

Bore 83 Actuating Knob 105

Open end 84 Threaded Shaft 106

Spring 85 Frustoconical locating section 107

Control member 86 Aperture 108

Recessed section. 87 Belt tracking adjustment

Outer profiled edge 88 arrangement 110

Stop 89 Knob 111

Tracking pin 90 Rotation axis X-X

Mounting head 91 Pivot axis Y-Y

Recess 92

Post 93

Aperture 94