Support head for use in helical flight forming apparatus

Abstract

A support head (400) for a blank (80) for use in helical flight forming apparatus (210), the blank having opposed main faces, an outer peripheral edge, a central hole having an inner peripheral edge, and a split extending from the outer peripheral edge to the inner peripheral edge so as to provide for opposed side edge sections. In one embodiment the support head (400) comprises: a main body part (410) having a main body axis (C-C) extending in a direction from one end thereof, a holder carriage part (416) for use with or including a blank holder having a blank receiving slot with a slot axis and gripper sections which contact the opposed main faces in the region of the side edge sections, when the blank is in an installed position, the holder carriage part (416) being operatively connectable to the main body part (410) in an adjustable fashion so that slot axis (D-D) can be inclined relative to the main body axis (C-C) in a number of different angular positions. In another embodiment the support head (500) comprises: a main body (512) which includes a first part (515) and a second part (516), the first and second parts being operatively connected together so is to the movable between an open position and a closed position in the direction of a displacement axis.

Description

SUPPORT HEAD FOR USE IN HELICAL FLIGHT FORMING APPARATUSTechnical Field

[0001] This disclosure relates generally to the manufacture of flights which are of a screw, helical or spiral shape. More particularly, the disclosure is concerned with an apparatus and a method of forming such flights and components therefor.Background Art

[0002] In international patent application PCT publication number WO 2017 / 156587 A1 , and European patent application 23179571.7, which will be hereinafter in this patent specification be referred to as the Prior Art Patent Specifications, there is disclosed an apparatus for forming helical type flights. The contents of the Prior Art Patent Specifications are herein incorporated in full into the present application by way of cross-reference. The Prior Art Patent Specifications which form part of the disclosure of this patent specification describes that apparatus in detail. The reference numerals used in the preamble of this patent specification are the same as those used to identify the parts and features described in the Prior Art Patent Specifications.

[0003] The inventor of the apparatus disclosed in the Prior Art Patent Specifications referred to is the same inventor of the matters disclosed in this specification. Any reference in this specification to prior art, or matter which is said to be known, is not to be taken as an acknowledgement or admission that such prior art or matter forms part of the common general knowledge in the field of invention to which this specification relates.

[0004] The apparatus 10, 210 described in the Prior Art Patent Specifications is for use in the formation of a helical screw flight from a blank 80 having an outer peripheral edge 82, a central hole 83 having an inner peripheral edge 84, and a split extending from the outer peripheral edge to the inner peripheral edge of the blank so as to provide for opposed side edge sections 82, 84. The apparatus comprises a drive 50, 250, first and second support heads 20, 220, 30, 230 configured to hold the blank 80 in the region of the opposed side edge sections 85, 86, the first and second support heads 20, 220, 30, 230 being arrangedfor the relative axial movement or displacement with respect to one another during formation of the helical flight in a direction of a main axis X-X from a performing position towards a formed position in response to actuation of the drive 50, 250. The first and second support heads 20, 220, 30, 230 are configured so as to provide for a plurality of position adjustments including a lateral position adjustment whereby the first and second support heads 20, 220, 30, 230 can be displaced or moved laterally with respect to the main axis X-X in a direction of respective lateral axes W-W, Y-Y during formation of the helical flight and a rotational position adjustment wherein at least one of the first and second support heads 20, 220, 30, 230 can be rotated about a rotation axis M-M which extends in a direction generally parallel to or coaxial with the main axis X-X during formation of the helical flight.

[0005] The first and second support heads 20, 220, 30, 230 each include a main body 22, 222, 32, 232 and a holder 24, 224 operatively mounted thereto, the holders 24, 224 configured to hold the blank 80 in the region of the opposed side edge sections 82, 84. In the embodiment shown the inner peripheral edge of the hole in the blank is adjacent the top of the slot. The holders 24, 224 are at least partially rotatable about respective pivot axes P- P which extend parallel to the respective lateral axes W-W, Y-Y. In one embodiment, each of the holders 24 comprise a one piece component including an elongated body 71 having opposed ends, a slot 72 extending from one end 73 towards and terminating short of the other end, the slot 72 comprising opposed V-shaped sides 76, 77 terminating at spaced apart inner edges 78 so as to provide for a gap or bight 79 therebetween. The first and second support heads include a housing cavity 79 in the main body 22, 222, 32 232 for receiving the holders 24, 224 therein. The holders 24, 224, include a curved outer wall and the housing cavity 79 comprises a complementary shaped curved inner wall enabling the relative rotation therebetween.

[0006] In one embodiment, the lateral movement of the first and second support heads 20, 220, 30, 230 in the direction of the lateral axes W-W, Y-Y is free movement absent of a drive, and the rotation of at least one of the support heads 20, 220, 30, 230 about the rotation axis M-M is also free movement absent of a drive. In another embodiment, the lateral movement of the first and second support heads 20, 220, 30, 230 in the direction of the lateral axes W-W, Y-Y is driven movement effected by a drive, and the rotation of at least one of the support heads 20, 220, 30, 230 about the rotation axis M-M is driven movementeffected by a drive. Each driven movement is optionally effected by a separate or different drive.

[0007] As explained in the Prior Art Patent specifications, the movement or position adjustments of the support heads enables the edge regions of the blank to substantially move in accordance with the natural or true forming path of the flight helix which can be maintained during the forming process. In the case of the free movement arrangement described this occurs naturally. In the case where the movements or position adjustments are driven, the drives for these movements are controlled and synchronised so as to produce the desired helical flight profile.

[0008] The first and second support heads 20, 220, 30, 230 are operatively mounted to guides 25, 35, 225, 235 along which the first and second support heads 20, 220, 30, 230 can track along in a direction of the lateral axes W-W, Y-Y. The guides comprise guide rods 25, 35, 225, 235. The second guide 85, 235 further includes a support 38 configured to facilitate the rotation of the second support head 30, 230 about the rotation axis M-M. In the embodiments shown, the lateral axes W-W and Y-Y are substantially at right angles to the axes X-X and M-M.

[0009] This disclosure is concerned with support heads which are suitable for use in apparatus for forming helical flights of the type described herein and in the Prior Art Patent Specifications. The helical flights can be mounted to a post, shaft or pipe. The support heads may also find use in other types of helical flight forming apparatus. Examples of types of helical flights include standard flights in which the flights are arranged substantially at right angles to the main axis referred to earlier, canted flights in which the flights are inclined at an angle less than 90° with respect to the main axis and ribbon flights in which the inner side of the flight is spaced from the shaft to which it is mounted via a series of support posts.Summary of Disclosure

[0010] In a first aspect embodiments are disclosed of a support head for a blank for use in helical flight forming apparatus, the blank having opposed main faces, an outer peripheral edge, a central hole having an inner peripheral edge, and a split extending from the outer peripheral edge to the inner peripheral edge so as to provide for opposed side edge sections,the support head comprising: a main body having a main body axis extending in a direction from one end thereof, a holder carriage for use with or including a blank holder having a blank receiving slot with a slot axis and gripper sections which contact the opposed main faces in the region of the side edge sections, when the blank is in an installed position, the holder carriage being operatively connectable to the main body in an adjustable fashion so that slot axis can be inclined relative to the main body axis in a number of different angular positions.

[0011] In certain embodiments, the support head includes a coupling assembly operatively connecting the main body to the holder carriage for relative movement there between along a path of travel.

[0012] In certain embodiments, the path of travel is a curved path.

[0013] In certain embodiments, the coupling assembly includes a guide on one of the main body or holder carriage, and a tracking follower on the other of the main body or holder carriage the tracking member being moveable along the guide in the direction of the path of travel.

[0014] In certain embodiments, the guide comprises a groove and the tracking member comprised a projection receivable within the groove for movement there along.

[0015] In certain embodiments, the support head includes a retention arrangement for retaining the main body and holder carriage in any one of the different positions.

[0016] In certain embodiments, the retention arrangement comprises cooperating toothed sections on the main body and the holder carriage.

[0017] In certain embodiments, the retention arrangement comprises a pinion gear on the main body and a toothed rack or segment on the holder carriage.

[0018] In certain embodiments, the pinion comprises a worm gear.

[0019] In certain embodiments, the holder carriage includes a housing to which the holder is mounted.

[0020] In a second aspect, embodiments are disclosed of a support head for a blank for use in helical flight forming apparatus, the blank having opposed main faces, an outer peripheral edge, a central hole having an inner peripheral edge, and a split extending fromthe outer peripheral edge to the inner peripheral edge so as to provide for opposed side sections, the support head comprising a main body which includes a first part and a second part, the first and second parts being operatively connected together so is to the movable between an open position and a closed position in the direction of a displacement axis.

[0021] In certain embodiments the support head further includes a guide arrangement for guiding movement of the first and second parts of the main body between the open and closed positions in the direction of the displacement axis.

[0022] In certain embodiments the guide arrangement includes one or more posts and associated apertures on respective ones of the first and second parts, the post being slidable along the aperture between the open and closed positions.

[0023] In certain embodiments further includes an actuator for causing the movement of the first and second parts between the closed positions.

[0024] In certain embodiments the actuator comprises a bolt having a bolt head threaded shank the bolt being mounted for rotation in the main body and is adapted to cooperate with a threaded aperture in one of the main body parts so that rotation of the bolt causes the two main body parts to move between the open and closed positions.

[0025] In certain embodiments further includes a blank holder housing for mounting a blank holder therein.

[0026] In certain embodiment the includes a blank holder which forms part of the main body.

[0027] In certain embodiments the blank holder comprises two sections, one being associated with the first main body part and the other being associated with the second main body part and arranged so that in the closed position they are configured to hold a blank and in the open position they are spaced to enable removed of nay the blank.Brief Description of the Drawings

[0028] Various aspects of the disclosure will become more fully understood from the following detailed description of preferred but non limiting embodiments thereof, described in connection with the accompanying drawings, wherein:

[0029] Figure 1 is a schematic isometric view of a support head according to one embodiment viewed from one end;

[0030] Figure 2 is a schematic isometric view of the support head shown in figure 1 viewed from the other end;

[0031] Figures 3 to 5 are side elevations of the support head shown in figures 1 and 2 in different operating positions;

[0032] Figure 6 is a schematic isometric view of a support head according to another embodiment viewed from one end;

[0033] Figure 7 is an exploded schematic isometric view of the support head shown in figure 6 viewed from the other end;

[0034] Figure 8 to 10 are side elevations of the support head shown in figures 6 and 7 in different operating positions;

[0035] Figure 11A is a side elevation of a support head according to yet another embodiment;

[0036] Figure 11 B is a sectional side elevation of the support head shown in figure 11 ;

[0037] Figures 12A and 12B are side elevations of support heads according to yet another embodiment;

[0038] Figure 13 is a side elevation of the support head shown in figures 6 to 10 together with a mounting body;

[0039] Figure 14 is an isometric view of part of an apparatus for forming helical flights with support heads of the type illustrated in figures 6 to 10;

[0040] Figure 15 is a side elevation of part of the apparatus shown in figure14;

[0041] Figure 16 is a side elevation of part of the apparatus shown in figures 14 and 15 when in a preforming position;

[0042] Figure 17 is an isometric view of part of the apparatus shown in figure 16;

[0043] Figure 18 is a side elevation of part of the apparatus shown in figures 16 and 17 when in a formed position;

[0044] Figure 19 is an isometric view of part of the apparatus shown in figure 18;

[0045] Figure 20 is a plan view of part of the apparatus shown in figures 18 and 19;

[0046] Figure 21 is a side elevation of a support head according to a further embodiment of support head when in a closed position;

[0047] Figures 22 and 23 are side elevations of the support head shown in figure 21 when in an open position;

[0048] Figures 24 and 25 are side elevations of the support head shown in figures 21 to 23 in the closed and open positions together with a helical flight;

[0049] Figure 26 is a sectional side elevation of the support head shown in figures 21 to 24;

[0050] Figure 27 is an isometric view of the support head shown in figures 21 to 24;

[0051] Figure 28 is an exploded view of the support head shown in figures 21 to 27;

[0052] Figure 29 is a side elevation of a support head according to a second embodiment when in a closed position;

[0053] Figure 30 is a similar view to that shown in figure 28 together with a helical flight;

[0054] Figures 31 and 32 are side elevations of the support head shown in figures 29 and 30 when in an open position;

[0055] Figure 33 is a plan view of the support head shown in figures 30 to 31 ;

[0056] Figure 34 is a sectional side elevation of the support head shown is figures 30 to 33;

[0057] Figures 35 and 36 are views of a blank for use with the support heads described; and

[0058] Figures 37 to 39 are views of a blank holder suitable for use with the support head shown in figures 21 to 34.Detailed Description of Preferred Embodiments

[0059] Referring to the drawings, in particular figures 1 to 12, there is illustrated three embodiments of a first type of support head 400 for use with a blank for apparatus for forming a helical flight from the blank. The support heads are suitable for use in flight forming apparatus of the type described in the Prior Art Patent Specifications. Figures 14 to 20 of the present case illustrate one form of apparatus which is similar to that described in the Prior Art Patent Specifications with reference to figures 14 to 20 therein. Where appropriate, the same reference numerals have been used to describe the same parts in each case. The support head 400 is illustrated as support heads 420 and 430 in figures 17 to 23.

[0060] One form of blank 80 is described in the Prior Art Patent Specifications and illustrated in figures 35 and 36 of this patent specification. The blank 80 is a generally annular body 81 in the form of a generally circular disc-like member having an outer peripheral edge 82, an inner or central hole 83 having an inner peripheral edge 84 with a split from the outer to the inner edges 82 to 84 to thereby provide for opposed side edges 85 and 86. In the embodiment shown, the blank 80 is generally circular with an inner circular hole, the outer peripheral edge and the inner peripheral edge being circumferential edges. In other embodiments, the blank need not be circular. The blank may be formed from any suitable material such as for example metals including steel, aluminium and may have some resilience or elastic deformation properties. A central axis A-A extends through the centre of the hole 83. The side edges 85 and 86 extend radially with respect to axis A-A. As such the side edges 85 and 86 are slightly inclined with respect to one another. The blank 80 has opposed main side faces which in the form shown is generally flat or planar in shape. However, it would be appreciated that other shapes such as having a dish-shaped profile, may be used.

[0061] As depicted in figures 14 to 20, the apparatus or machine 210 includes a main structure, frame or housing 212 which in the form shown comprises end sections 213 and 214 and an intermediate section 211 which form a rigid structure. The structure or housing 212 includes a flight forming zone 217 between the end sections 213 and 214.

[0062] The apparatus 210 further includes a drive 250 which comprise a motor 253 arranged to power a linear actuator 251 in the form of a ballscrew 254. Power is transmitted from the motor 253 to the ballscrew 254 via a belt (not shown) which extends around pulleys255 and 256. The ballscrew 254 includes a ballscrew nut 257 and a sleeve 258. Rotation of the ballscrew 254 causes linear movement of the nut 257 and the sleeve 258 in the direction of main axis X-X.

[0063] The apparatus 210 further includes first and second support heads 420 and 430 which in use are adapted to hold the blank 80 in the region of the side edges 85 and 86. That is, the support head 420 is configured so as to hold the blank 80 in a side edge region of side edge 85 and support head 430 is configured so as to hold the blank 80 in a side edge region of side edge 86. The side edge region as used herein does not necessarily mean at the side edge but includes a region spaced from the side edge. The first support head 420 is an axially displaceable head arranged for displacement or movement in the direction of the main axis X-X in response to actuation of the drive 250. The second support head 430 is mounted to end section so as to be inhibited from movement in the direction of the main axis X-X. The support heads 420 and 430 are best illustrated in figures 1 to 12. In certain embodiments, the second support head 430 could also be mounted for axial movement.

[0064] The first support head 420 is operatively connected to the drive 250 through a mounting 260 which includes a mounting plate 263 which is operatively connected to the sleeve 258. The plate 263 is carried on guides 265 and 266 which in the form shown comprise guide rods 267 and 268 and associated sleeves 261 and 264. The guide rods 267 and 268 move through guide sleeves mounting 261 and 264 during axial linear movement of the sleeve 258.

[0065] The first support head 420 is operatively connected to a mounting member 222, which is operatively mounted to a mounting plate 263 in the manner hereinafter described.

[0066] The first support head 420 is arranged so that a lateral displacement of at least part thereof can be effected in a lateral direction with respect to main axis X-X. The lateral displacement is generally in the direction of lateral axis W-W (figure 18). The lateral displacement can be effected in different ways. For example, as shown, the mounting member 222 can be mounted for lateral displacement. To this end the mounting member 222 can be mounted on guides in the form shown comprises guide rods 225 secured to mounting member 222 which is secured to the mounting plate 263. The rods 225 extendthrough apertures in the mounting member 222 so that the mounting member 222 can track along the rods 225 in the direction of axis W-W.

[0067] In this embodiment, the lateral movement of the mounting member 222 and the first support head 420 is driven for movement in the direction of axis W-W and to this end a drive motor 226 is mounted to the plate 263. A drive belt (not shown) transmits power to screw 227 via pulleys 228 and 229. Rotation of the screw 227 causes movement of the main body 222 therealong in the direction of axis W-W. This is clearly illustrated in the Prior Art Patent Specifications.

[0068] The second support head 430 can be similar in form to the first support head 420. The second support head 430 is operatively connected to a mounting member 232 which is operatively mounted to end section 214 of the main structure or housing 212. The mounting member 232 is operatively connected to a support 238 which is mounted to the end section 214 through a shaft 233 and associated bearing 231 , similar to that shown in figure 52 of the Prior Art Patent Specifications, for rotation about an axis M-M which is parallel or co-axial with the main axis X-X. The support 238 is in the form of a plate member.

[0069] In a similar fashion to the first support head 420, the second support head 430 is arranged so that a lateral displacement of at least part thereof can be effected. The lateral displacement is generally in the direction of axis Y-Y. Because the mounting member 232 can rotate about axis M-M, it will be appreciated that the angular position of lateral axis Y-Y will change. The mounting member 232 can be mounted on guides in the form of guide rods 235 secured to mounting plates 237 which are secured to support plate 238, similar to that shown in figures 45 and 46 of the Prior Art Patent Specifications. The rods 235 extend through apertures in the mounting member 232 in a similar fashion as described with reference to the first support head 420 so that the body portion can track along the rods 235. As shown in this embodiment, lateral axes W-W and Y-Y are substantially at right angles to axes X-X and M-M.

[0070] In this embodiment, the rotational movement of the mounting member 232 of the second support head 430 is driven by a drive motor 286 which is mounted to a wall of end section 214, similar to that shown in figure 52 of the Prior Art Patent Specifications. A drivebelt (not shown) transmits power via pulleys 288 and 289. Rotation of the pulley 289 causes rotation of the main body 232 about axis M-M.

[0071] Furthermore, in this embodiment, the lateral movement of the mounting member 232 of the second support head 430 is driven and to this end a drive motor 236 is mounted to plate 238, similar to that shown in figure 46 of the Prior Art Patent Specifications. A drive belt (not shown) transmits power to screw 257 via pulleys 248 and 249. Rotation of the screw 257 causes movement of the mounting member 232 therealong in the directions of axis Y- Y. This is clearly illustrated in the Prior Art Patent Specifications.

[0072] Figures 1 to 5, 6 to 10 and 11 and 12 illustrate various embodiments of support head 400 which are suitable for use in the apparatus shown in figures 14 to 20. As mentioned earlier, the support head 400 may be used as the first and second support heads 420 and 430 as identified in figures 17 to 23. As shown in figures 1 to 12, the support head 400 comprises two main parts including a main body part 410 having an outer end 411 with a main body part axis C-C extending from the outer end 411 (figures 3 and 8). When installed or fitted to the apparatus 210, the axis C-C is substantially coaxial with or parallel to the main axis X-X of the apparatus 210.

[0073] The support head 400 further includes a holder carriage part 412 which is operatively connected to the main body part 410 in an adjustable fashion. The holder carriage part 412 comprises a lower base section 415 and an upper wall section 416 having a top side 417. The holder carriage part 412 further includes a housing 414 for mounting a blank holder to the holder carriage part 412. The housing 414 comprises a cavity 418 which extends into the wall section 416 from the top side 417. The cavity has a longitudinally extending axis D-D which extends from the top side.

[0074] An example of a type of blank holder which can be used with the support head is illustrated in figure 37 to 39. As shown, the holder 24 is a one piece component having an elongated body with opposed ends. A slot 78 extends from one end towards the other end and terminates short of that end. The slot 78 has opposed V-shaped sides 76 and 77 terminating at spaced apart inner edges so as to provide for a gap 78 therebetween. The inner edges form gripping sections which grip the blank on the opposed faces thereof. Theslot 78 has a slot axis P-P which extends in a direction between the ends. The holder 80 can be mounted within the cavity 418 with the slot axis P-P being parallel or coaxial with cavity axis D-D so as to be rotatable about the slot axis P-P. The slot axis P-P corresponds to the axis P-P as illustrated in the drawings of the apparatus 210 described with reference to figures 14 to 20.

[0075] The adjustment enables the holder carriage part 412 to effectively pivot or rotate relative to the main body part 410 so that the angle between the axes C-C and D-D can change. Three different angular positions are illustrated in figures 3 to 5 and figures 8 to 10. The purpose of the angular changes will be explained hereinafter.

[0076] The support head 400 further includes a coupling assembly 440 operatively connecting the holder carriage part 412 to the main body part 410 so as to facilitate adjustment of the positions of the two parts relative to one another. The coupling assembly 440 enables relative movement between the holder carriage part 412 and main body part 410 along a path of travel E-E.

[0077] The coupling assembly 440 comprises a guide 442 on one of the parts and a follower 444 on the other of the parts, the follower being configured to track along the guide 442 in the direction of the travel path E-E.

[0078] The guide may be in the form of a T-shaped groove 446 and the follower in the form of a complementary shaped projection 448 receivable within the groove 446 for movement therealong. The groove 446 may comprise a main part 450 and a mouth 452 and the projection 448 may comprise a head 454 and a neck 456.

[0079] The head 454 of the projection 448 is located within the main part 450 of the groove 446 with the neck 456 extending through the mouth 452. In the embodiments illustrated, the groove 446 is on the main body part 410 and the projection 448 is on the holder carriage part 412 although it is understood that this could be reversed.

[0080] In the embodiment of figures 1 to 5, the adjustment between the two parts is effected manually. The two parts are moved relative to one another till the desired positionis reached and a retention spigot 460 is moved into a position where further movement between the two parts is inhibited.

[0081] In the embodiment of figures 6 to 10, the two parts are operatively connected together through an adjustment mechanism which comprises a geartrain having cooperating toothed sections which are arranged in meshing engagement. The gear train comprises a gear wheel in the form of a worm gear 482 arranged to meshingly engage with a toothed section 480 of a bar so that rotation of the worm gear 482 causes movement of the bar.

[0082] The coupling assembly 440 further includes a retention arrangement 460 for retaining the two parts in one of a number of positions relative to one another. Three different positions of the two parts relative to one another are shown in figures 3 to 5 and 8 to 10. As is apparent, the axis P-P is included at different angles to the axis C-C, the reasons for this which will be explained later.

[0083] In the embodiment of figures 1 to 5, the arrangement comprises one or more bolts, screws of spigots 461 operable to releasably retain the two parts together.

[0084] In the embodiment of figures 6 to 10, the retention arrangement comprises cooperating toothed sections in meshing engagement.

[0085] The embodiment illustrated in figures 11A and 11 B is similar to that shown in figures 1 to 10 and where appropriate, the same reference numerals used in relation to the embodiment of figures 1 to 10 are used to identify similar parts in figures 11A and 11 B. In this embodiment, the main body part 411 and the holder carriage part 412 comprise a plurality of apertures 464 and 465, which are arranged so that they can overlie one another in different positions along the travel path E-E (see figure 8). When the two parts 411 and 412 are in the desired position relative to one another, one or more pins can pass through one or more of the aligned pairs of apertures to retain the two parts in position relative to one another. An adjustment device 483 is operable to move the two parts 411 and 412 relative to one another along the travel path E-E when the pin or pins are removed from the overlying apertures. In the embodiment illustrated, the adjustment device 483 is in the form of a turnbuckle.

[0086] The embodiments illustrated in figures 12A and 12B are similar to that shown in figures 1 to 11A / B. In the embodiments of figures 12A and 12B a ratchet mechanism 470 is arranged to hold the main body part 411 and the holder carriage part 412 in one of a number of positions relative to one another. The ratchet mechanism 470 comprises a ratchet bar 472 on the holder carriage part 412. The ratchet bar 472 has a series of ratchet teeth 473 thereon which are arranged along the travel path E-E as shown in figure 8. Thus the ratchet bar 472 is adapted to move along the travel path E-E with the holder carriage part 412.

[0087] An actuator, which in the form shown comprises a pinion 485, causes movement of the ratchet bar 472 and holder carriage part 412 along the travel path E-E. The pinion 485 is rotatably mounted to the main body part 411 and includes a series of teeth 486 which meshingly engage with the teeth 473 on the ratchet bar 472. A drive knob 487 (or another suitable drive member) drives the rotation of the pinion 485.

[0088] The ratchet mechanism 470 further includes a first pawl 475 and a second pawl 477 each operatively engageable with the ratchet teeth 473. The pawls 475 and 477 are mounted for movement between an engaged position in which the pawls are in operative engagement with the ratchet teeth 473 and a disengaged or inoperative position in which they are clear of the ratchet teeth 473.

[0089] In figures 12A and 12B pawl 475 is in the disengaged inoperative position and pawl 477 is in the engaged position. In the engaged position the pawl enables movement of the ratchet bar in one direction but inhibits its movement in the other direction. In the embodiment of figure 12A springs 476 and 478 urge the pawls into the engaged position.

[0090] In order to enable movement of carriage 412 one or both of the pawls are positioned in the inoperative position. As shown in figures 12A and 12B pawl 477 is in the engaged position in which it contacts the teeth 473 of the ratchet bar 472. Pawl 475 is shown in the inoperative position in which it is out of contact with the teeth 473.

[0091] In the particular configuration illustrated, rotation of the pinion 485 in an anticlockwise direction causes movement of the ratchet bar 472 in a clockwise direction. In order to enable travel of the ratchet bar 472 in the anticlockwise direction, pawl 477 is movedto its inoperative position and pawl 475 is moved into its engaged position. During this anticlockwise motion of the ratchet bar the pawl 477 slides over the teeth 473 thereby permitting movement of the ratchet bar. Movement of the ratchet bar 472 in the opposite direction is inhibited because the pawl 477 catches on the teeth 473 thereby preventing movement in that direction. Pawl 475 and the ratchet bar 472 operate in a similar fashion when the ratchet bar is required to move in the opposite direction to that shown.

[0092] The pawls 475, 477 are depicted with springs 476, 478, but it will be appreciated that they may alternatively be controlled with another suitable control means, such as magnets, solenoids, electric motors or some other spring or biasing member rotationally acting on a shaft associated with each of the pawls 475, 477. It will be appreciated that the pawls 475, 477 are configured for selective transition between operative engagement and the inoperative position.

[0093] The operation of the apparatus shown in figures 14 to 20 will hereinafter be described. Firstly, the two support heads 420 and 430 are adjusted so that the angle of axis P-P (D-D) is at a chosen angle with respect to axis X-X (C-C). The angle selected determines the nature of the helical profile to be formed. For example, if both support heads 420 and 430 are in the position shown in figure 4 (first embodiment) and figure 9 (the second embodiment), the helical profile formed will be a standard or normal profile. If one or both of the axes P-P (D-D) are inclined at an angle with respect to axis X-X (C-C) as shown in figures 3 and 5 in the first embodiment and figures 8 and 10 in the second embodiment then a canted helical profile of selected cant angle can be formed. By having the angle of inclination of the support heads at different angles, a progressive canted profile can be formed.

[0094] Once the angles are chosen, the support heads can be mounted to respective mountings 222 and 232. The preforming position of the support heads is illustrated in figures 18 to 20, wherein they are disposed adjacent one another with the blank 80 mounted thereto. The drive 250 is then activated so that the support heads are drawn apart in the direction of the axis X-X thereby forming the selected helical profile. During the movement of the support heads in the direction of axis X-X they can also move in the direction of lateral axes W-W and Y-Y and support head 230 / 430 can rotate about axis M-M. These movement can occurduring formation of the helical flight. These movements are illustrated in figures 21 to 23 and described in detail in the Prior Art Patent Specifications.

[0095] It would be appreciated that a number of different helical profiles can be formed using support heads of the type described in association with the apparatus described.

[0096] Referring in particular to figures 21 to 33 of the drawings there is illustrated two embodiments of a further type support head 500 for use with a blank for apparatus for forming a helical flight from the blank. The support heads are suitable for use in flight forming apparatus of the type described in the Prior Art Patent Specifications and as described herein earlier.

[0097] An example of one form of blank 80 with which the support head 500 is suitable for use is illustrated in figures 35 and 36 as described earlier. The blank 80 is a generally annular body 81 in the form of a generally circular disc-like member having an outer peripheral edge 82, an inner or central hole 83 having an inner peripheral edge 84 with a split from the outer to the inner edge 82 to 84 thereby providing for opposed side edges 85 and 86. In the embodiment shown the blank 80 is generally circular with an inner circular hole, the outer peripheral edge and the inner peripheral edge being circumferential edges. In other embodiments the blank need not be circular. The blank may be formed from any suitable material such as for example metals including steel, aluminium and may have some resilience or elastic deformation properties. A central axis A-A extends through the centre of the hole 83. The side edges 85 and 86 extend radially with respect to axis A-A. As such the side edges are slightly inclined with respect to one another. The blank has opposed main side faces which in the form shown is generally flat or planar in shape. It could, however, be other shapes such as having a dish-shaped profile.

[0098] Referring to figures 21 to 34 there is illustrated embodiments of this type support head 500 which comprises a main body 512. The main body of the support head 500 comprises a first part 515 and a second part 516 which are operatively connected together so as to be movable relative to one another in the direction of displacement axis R-R (figures 22 and 23) between a closed position as shown in figures 21 and 24 for example and an open position as shown in figures 22 and 25. Each of the first and second parts have anupper side 513, a lower side 514 and an inner side 511. The inner sides 511 face one another. In the closed position the inner sides abut one another and in the open position they are spaced apart.

[0099] The second main body part 516 is adapted for securement to a mounting member 517 which in turn can be operatively connected to helical flight forming apparatus of the type for example, shown in the Prior Art Patent Specifications. The support head 500 can replace the support heads shown in the Prior Art Patent Specifications so as to operate in similar fashion.

[0100] The two parts 515 and 516 include a guide arrangement 520 (figure 8) for guiding the relative movement between the open and closed positions in the direction of displacement axis R-R. The guide arrangement 520 in the form shown comprises posts 521 and associated apertures 525. The posts 521 may be fixedly mounted to one of the parts and are slidably movable along apertures 525 in the other part. The posts are secured to the first part 515 of the main body 512 and extend from the inner side 511 thereof. The posts are slidably receivable in apertures 525. There is further provided a spring 526 which is disposed within the apertures 525 and arranged so as to provide a biassing force which urges the two parts away from one another towards the open position. This arrangement is clearly illustrated in figure 8.

[0101] The support head 500 further includes an actuator 522 arranged so that activation thereof causes the relative movement of the two parts between the open and closed positions. In the embodiment illustrated the actuator 522 comprises a bolt 523 having a head 527 and threaded shank 528 which is adapted to meshingly engage threaded sections in aperture 529. The bolt is mounted for rotation within aligned apertures 529 in the first and second parts. The bolt 523 comprises a head 527 and a shank 528 at least a portion of the shank having a thread therein. The threaded portion is adapted to cooperate with a complementary threaded portion of aperture 529 in one of the parts so that rotation of the bolt will cause relative movement between the two parts in the direction of displacement axis R-R. Rotation of the bolt 523 causes the relative movement of the two parts between the open and closed positions.

[0102] The support head 500 as illustrated in figures 21 to 28 is adapted for use with a blank holder 24 of type illustrated in figures 17 to 19 which comprises an elongated body 71 having opposed ends, a slot 72 extending from one end 73 towards and terminating short of the other end, the slot 72 comprising opposed V-shaped sides 76, 77 terminating at spaced apart inner edges 78 so as to provide for a gap or bight 79 therebetween.

[0103] In the embodiment of figures 21 to 28 support head 500 includes a housing 530 for mounting a blank holder 24 therein. The housing 530 comprises two sections 531 and 532, one section being associated with the first main body part and the other being associated with the second body part. When in the closed position the two sections together form the housing 530 which as shown is in the form of a cavity sized so as to receive the blank holder therein. The cavity extends from the upper side inwardly. Thus in the closed position the blank holder is received snugly within the cavity and in the open position can be readily removed. An advantage of the arrangement is that the blank 80 or helical flight formed can be readily removed with minimal force after forming by moving the support head 500 to the open position which inhibits the blank holder 560 from getting stuck in the support head 500.

[0104] The holder 24 may be mounted so as to be at least partially rotatable about axis P-P or in another arrangement fixed against rotation.

[0105] The support head 500 may further include a latch 536 which is pivotally mounted to one of the parts the latch having a lug 537 which can engage against a shoulder 538 when in the closed position.

[0106] Figures 29 to 34 illustrate a further embodiment which is similar in structure to that of the first embodiment and like parts have been identified by the same reference numerals as used in the first embodiment.

[0107] This embodiment differs from the first embodiment in that a blank holder 560 forms part of the main body of the support head rather than as a separate component. As shown the blank holder 560 comprises two sections 561 and 562, one being on the inner sides of the first main body part and the other being on the inner side of the second mainbody part. The holder sections 561 and 562 each have a gripping edge which, when the main body is in the closed position are adapted to grip the blank.

[0108] Throughout this specification, unless the context requires otherwise, the word “comprise”, and any variations thereof such as “comprises” or “comprising”, are to be interpreted in a non-exhaustive sense.

[0109] Wherever it is used, 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.

[0110] In the foregoing description of preferred embodiments, specific terminology had been resorted to for the sake of clarity. However, the invention is not intended to be limited to the 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 constructed as limiting terms.

[0111] In addition, the foregoing describes only some embodiments of the invention(s), and alteration, modifications, additions and / or changes can be made thereto without departing from the scope and spirit of the disclosed embodiments, the embodiments being illustrative and not restrictive.

[0112] Furthermore, invention(s) have been described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, included withing the spirit and scope of the invention(s). Also, the various embodiments, e.g., aspects of one embodiment may be combined with aspects of another embodiment to realise yet other embodiments. Further, each independent feature or component of any given assembly may constitute an additional embodiment.Table of PartsSupport Head 400 / 420 / 430Main Body Part 410Outer End 411Main Body Axis C-CHolder Carriage Part 412Lower Base Section 415Upper Wall Section 416Top Side 417Housing 414Housing Cavity 418Blank Holder 416Blank Receiving Slot 420Slot Axis P-PGripper Sections 424Coupling Assembly 430Travel Path E-EGuide 432Tracking Follower 434Groove 446Projection 438Retention Arrangement 440Spigot 460Follower 444Toothed Pinion 446Shaped Projection 448Housing 450Cavity 452Head 454Neck 456Toothed Section 480Worm Gear 482Apparatus 210Main structure or housing 212End sections 213 / 214Intermediate section 211Flight forming zone 217Drive 250Motor 253Linear actuator 251Ballscrew 254Pulleys 255 / 256Ballscrew nut 257Sleeve 258First support head 420Second support head 430Mounting 260Mounting plate 263Guides 265 / 266Mounting sleeves 261 / 264Guide sleeves 267 / 268Mounting member 222Blank gripper or holder 224Housing 215Ledge 221Mounting member 222Groove or slot 223Lever 219Guide rods 225Latch 270Drive motor 226Screw 227Pulleys 228 / 229Support 238Plate member 237Shaft 233Bearing 231Ledge 272Latch 290Blank holder 234Gripper elements 231Motor 246Pulleys 248 / 249Motor 286Pulleys 288 / 289Bight 278Main body 291Slot 292Sides 274 / 275Edges 276 / 277Bight 278Counterweight 290Bearing 231Support Head 500Main Body 512Inner Side 511Upper Side 513Lower Side 514First Part 515Second Part 516Mounting Member 517Guide Arrangement 520Actuator 522Bolt 523Head 527Shank 528Aperture 529Aperture 524Posts 521Apertures 525Springs 526Latch 536Lug 537Shoulder 538Housing 531Cavity 532Displacement Axis R-RCavity Axis S-SBlank Holder 560Sections 561 / 562Blank Holder 24Slot 78V-Shaped Sides 76 / 77Gap 79Blank 80Body 81Outer Peripheral Edge 82Central Hole 83Inner Peripheral Edge 84Side Edges 85 / 86 _

Claims

1. Claims1 . A support head (400) for a blank (80) for use in helical flight forming apparatus (210), the blank having opposed main faces, an outer peripheral edge, a central hole having an inner peripheral edge, and a split extending from the outer peripheral edge to the inner peripheral edge so as to provide for opposed side edge sections, the support head (400) comprising: a main body part (410) having a main body axis (C-C) extending in a direction from one end thereof, a holder carriage part (416) for use with or including a blank holder having a blank receiving slot with a slot axis and gripper sections which contact the opposed main faces in the region of the side edge sections, when the blank is in an installed position, the holder carriage part (416) being operatively connectable to the main body part (410) in an adjustable fashion so that slot axis (D-D) can be inclined relative to the main body axis (C-C) in a number of different angular positions.

2. A support head according to claim 1 including a coupling assembly (430) operatively connecting the main body part (410) to the holder carriage part (416) for relative movement there between along a path of travel (E-E).

3. A support head according to claim 2 wherein the path of travel is a curved path.

4. A support head according to claim 2 or claim 3 wherein the coupling assembly includes a guide (432) on one of the main body part or holder carriage part and a tracking follower (434) on the other of the main body or holder carriage, the tracking member being moveable along the guide.

5. A support head according to claim 4 wherein the guide (432) comprises a groove (446) and the tracking follower comprised a projection (438) receivable within the groove for movement therealong.

6. A support element according to any one of claims 1 to 5 including a retention arrangement for retaining the main body part and holder carriage in any one of the positions.

7. A support head according to claim 6, wherein the retention arrangement comprises cooperating toothed sections on the main body part and the holder carriage part.

8. A support head according to claim 7, wherein the retention arrangement comprises a toothed pinion gear on the main body part and a toothed bar on the holder carriage part.

9. A support head according to claim 8, wherein the pinion comprises a worm gear.

10. A support head according to any one of claims 1 to 9, wherein the holder carriage includes a housing to which the holder in mounted.

11. A support head (500) for a blank (80) for use in helical flight forming apparatus, the blank having opposed main faces, an outer peripheral edge, a central hole having an inner peripheral edge, and a split extending from the outer peripheral edge to the inner peripheral edge so as to provide for opposed side sections, the support head (500) comprising: a main body (512) which includes a first part (515) and a second part (516), the first and second parts being operatively connected together so is to the movable between an open position and a closed position in the direction of a displacement axis.

12. A support head according to claim 1 further including a guide arrangement for limiting the movement of the first and second parts of the main body between the open and closed positions.

13. A support head according to claim 2 wherein the guide arrangement includes one or more posts and associated apertures on respective ones of the first and second parts the post being slidable along the aperture between the open and closed positions.

14. A support head according to any one of claims 1 to 3 further including an actuator moving the first and second parts between the closed positions.

15. A support head according to claim 4 wherein the actuator comprises a bolt having a threaded shank the bolt being mounted for rotation in the main body and is adapted to cooperate with a threaded aperture in one of the main body parts so that rotation of the bolt causes the two main body parts to move between the open and closed positions.

16. A support head according to any one of claims 1 to 5 further including a blank holder housing for mounting a blank holder therein.

17. A support head according to any one of claims 1 to 5 including a blank holder which forms part of the main body.

18. A support head according to claim 7 wherein the blank holder comprises two sections, one being associated with the first main body part and the other being associated with the second main body part and arranged so that in the closed position they are configured to hold a blank and in the open position they are spaced to enable removed of nay the blank.

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