AU7975591A - Modular die lifting system - Google Patents

Description

MODULAR DIE LIFTING SYSTEM This invention relates to an improved die lifter system, and more particularly to an improved die lifter assembly of modular construction for movably supporting a die in a press bed. The lifter system may also be used for the transfer and location of heavy tools or pallets along a support bed.

It is of course well known to utilise spring loaded and hydraulic die lifters of inverted T-shaped construction for supporting and transferring a die into and out of a power press. Conventionally, these die lifters are installed in T- slots formed in the press bed and then locked in place, the size of the press bed determining the length and size of the required lifter assembly. In the case of hydraulic die lifters, supporting balls or rollers are lifted by hydraulic pressure, whereas in the case of spring loaded di lifters, . springs are used to elevate the balls, which when elevated, make contact with and support the die positioned on top thereof. The die can then freely move along the length of the lifter. The Applicant is also aware of a die lifter system of modular construction comprising a plurality of die lifter block modules each having an inverted T-shape, with the modular blocks being secured together in end-to-end relation by means of a pair of parallel elongate connector or tie rods which extend through elongate passageways formed adjacent the longitudinal margins of the blocks in the horizontal limb portions thereof. The connector rods have threaded ends which threadably engage securing nuts to prevent displacement of the rods and in turn to ensure that the modular blocks are firmly held one against the other in a straight line. The number of modular blocks is determined by the size and configuration of the press bed. This system is not generally satisfactory since the assembly of the modular blocks and the installation of the assembly into the press bed is relatively time consuming.

It is the main object of the present invention to provide an improved die lifter system of modular construction which enables the modular die lifter elements to be quickly and easily assembled and disassembled, and hence permit different configurations to be readily achieved.

It is a further object to provide an improved modular die lifter system which will allow single modules to be easily removed and replaced for purposes of repair or of change of position within the press bed.

It is a still further object of the present invention to provide an improved die lifter system of modular construction which is of simple design, of relatively low cost and which is able to be easily packaged and handled for transport purposes.

In one of its forms, the present invention is directed to an improved hydraulic modular die or tool lifter assembly comprising a plurality of die lifter modular blocks interconnectable in end-to-end relation to form a horizontal row, each said block having a top wall, a bottom wall, a pair of opposite parallel planar end walls and a pair of opposite parallel planar side walls, a horizontal fluid flow passageway extending longitudinally through said block, a plurality of spaced apart parallel bores extending vertically inwardly from said top wall and communicating with said passageway, plungers reciprocally movable within said bores between retracted and extended positions, each said plunger carrying at its upper end a rotatable load bearing element, arranged so that upon admission of pressure fluid in said passageway, the plungers are moved to their extended or raised positions wherein said load bearing elements project above the plane of said top wall to thereby support the die or tool in a raised position above said plane, characterised in that each said block has a male joining element integral with and projecting from one of its said end walls and a female joining element in its other said end wall arranged to co-operate with a male joining element of an adjacent said block for releasably lockingly engaging said blocks in said end-to-end relation, said blocks when so interconnected, having their passageways in fluid flow communication with one another, and sealing means for effecting a seal between mating surfaces of the interlocking male and female joining elements to prevent loss of fluid pressure.

Preferably the male joining element comprises a cylindrical portion projecting from said one of said end walls and which joins with a part-circular lug member arranged to lockingly engage in a female cavity in the other end wall of an adjacent module, there being a central bore extending through the male element to permit the passage of hydraulic fluid therethrough, and wherein said sealing means comprises a resilient O-ring located in an annular groove formed in the end face of the lug member and which surrounds said central bore, said O-ring being arranged to be resiliently compressed against the base wall of the cavity when the lug member is lockingly .engaged therein.

Preferably the female cavity comprises walls defining a slotted opening extending inwardly from the end wall of said block, the opening being shaped and dimensioned so as to allow the insertion of the lug portion thereinto only when the blocks are positioned at an angle, preferably 90", to one another, said slotted opening connecting with a circular recessed portion, the depth of which approximately equals the axial thickness of said lug member. With this arrangement, the lug member of the male joining element is inserted through the slotted opening and into said circular recessed portion of the female joining element, and the blocks rotated through an angle of 90^*, to horizontally align them, whereupon the joining elements are firmly interlocked and the blocks restrained against axial separation. Preferably, a pair of terminal end blocks are provided and connect to respective outermost ones of the blocks of the horizontal row, the connection being effected in an identical manner to that described hereinabove.

Preferably one of the end blocks is provided with a through-passageway extending between the upper and lower faces thereof for receiving a retaining member, e.g. a set screw, for releasably securing said one end block to the press bed, while the other end block is formed with a horizontally extending through-passageway which at one end communicates with the central bore extending through the male joining element of an adjacent block and at its other end to an hydraulic fluid supply line.

It will of course be realised that the spigot/socket bayonet cap type connection between adjacent die lifter module elements and between the end blocks and their associated module elements, must be capable of withholding significant hydraulic pressures, and to this end the male and female joining elements are required to be machined to close tolerances to ensure proper sealing engagement between mating surfaces of the blocks and true alignment of the end blocks relative to the module element(s) and to each other. In order to more fully explain the present invention, several embodiments are described hereunder in some further detail with reference to the accompanying drawings wherein:

Fig 1 is a side elevational view of a part-assembled die lifter assembly constructed according to one embodiment of this invention;

Fig 2 is a plan view of the assembly shown in Fig 1; Fig 3 is a partly-sectioned elevational view of a die lifter module element shown in Fig 1;

Fig 4 is an end elevational view of the module element of Fig 3 looking in the direction of arrow A;

Fig 5 is an end elevational view of the module element of Fig 3 looking in the direction of arrow B;

Figs 6a and 6b are transverse cross-sectional views taken through a block showing the plunger (supporting a roller, in lieu of a ball element) in the lowered and raised positions respectively;

Fig 7 is a fragmentary, part sectional view of a ball- locking wedge fitted in each of the module elements;

Fig 8 is a perspective view of an assembled die lifter assembly according to a second embodiment of the invention; Figs 9a and 9b are perspective views of the end blocks shown in Figs 1 and 8; whilst Fig 10 is a fragmentary elevational view of a die lifter assembly installed in the existing T-slots of a press bed, one of the lifters shown in the raised position, the other in a lowered position. Referring firstly to the embodiment shown in Figs 1 to 7 of the drawings, there is shown an hydraulic modular die lifter assembly 10 comprising a plurality of interconnected, horizontally aligned die lifter modular blocks 11, and end blocks 12, 13, the adjacent end faces of pairs of adjacent blocks 11, 12, 13 being in contiguous relation. The blocks 11 are releasably interlocked with one another, whilst the end^' blocks 12, 13 are interlocked with respective outermost blocks 11, by interengage ent means which in this embodiment is of the bayonet-cap type comprising a male joining element 14 and a female joining element 15, integrally formed with the block end walls. In this embodiment, the blocks 11, 12, 13 are formed, eg by a milling operation, from bright mild steel (CS 1240).

As shown in Fig 3, each die lifter block 11, in accordance with known art, is formed with cylindrical bores 16 extending vertically inwardly from its upper face 17 and in each of which is housed a vertically movable plunger 19 on the upper end of which is mounted a freely movable ball bearing 20, the plungers 19, along with the balls 20, being lifted to a raised position to support a die thereon by means of hydraulic pressure. Each ball 20 is itself supported on a bed of small diameter ball bearings (not shown) . Each cylindrical bore 16 communicates with an hydraulic fluid passageway 21 which extends horizontally through the length of the block 11. A C-shaped elongate locating rod 23 extends through the passageway 21, and passes through slotted openings 24 formed in the plungers 19 (refer Figs 6a and 6b) , the rod 23 limiting the extent of vertical movement of the plungers 19 and preventing tilting movement thereof. The rod 23 is hollow to permit hydraulic fluid to flow therethrough, and has an axial slotted opening in its wall to permit the fluid to pass into the passageways 21 and the bores 16. Each male joining element 14 comprises a cylindrical portion 25 which projects from end face 26 of the block 11, the portion 25 terminating in a part-circular lug 27, the periphery of the lug 27 being defined by a pair of opposed arcuate surfaces 28 which are joined by a pair of opposed linear surfaces 29. A central bore 30, which is co-axially aligned with passageway 21, extends through the male joining element 14 and terminates at its outer end in an O-ring receiving groove 31 for receiving an O-ring 34, the depth of the groove 31 and the thickness of the O-ring 34 being sized such that the O-ring 34 projects axially beyond the planar end face 35 of the lug 27 (refer Fig 3).

Each female joining element 15 is constituted by a cavity 36 extending inwardly from the opposite planar end face 37 of the block 11, the cavity 36 being defined by slot forming walls 40 which join to a circular recessed portion 41, the diameter of the circular recess 41 being greater than the transverse width off the slot formed by walls 40 (measured across its minor axis), to thereby form diametrically opposed radial pockets 43. The recessed portion 41 is co-axial with an communicates with passageway 21.

The lug 27 and the cavity 36 are dimensioned and configured so that the lug 27 can pass axially through the slot 40 only when the blocks 11 to be joined are angularly offset to one another, in this embodiment the angle being 90', namely when the margins 29 of the lug 27 are parallel with the linear sides of the slot 40. Thereafter, the lug 27 is snugly received in the recess 41, one of the blocks 11 then being rotated through 90" so that the joined blocks 11 are horizontally aligned. In this position the diametrically opposed arcuate lug portions of the lug 27 are lockingly engaged within respective pockets 43, and the blocks 11 are tightly retained together with their end faces 26, 37 in mating relationship with the sealing O-ring 34 being compressed against its resilience into engagement with the planar base wall 44, of the recessed portion 41 to form a seal. With the blocks 11 thus interlocked, their passageways 21 are fluidly interconnected by means of the bore 30 of the male joining element 14.

The end blocks 12, 13 are separately shown in Figs 9a and 9b and interlock with respective outermost blocks 11 to complete the assembly 10. End block 13 comprises a vertically extending anchor bolt hole 45 which is arranged to receive a set screw or bolt (not shown) for removably securing the block 13, and in turn the interconnected blocks 11 of the die lifter block assembly 10 to the press bed. An hydraulic fluid passageway 46 in the block 13 communicates with cavity 36 which forms a female joining element identical to that previously described and also communicates with an air bleed hole 49 containing a bleed screw (not shown) to enable the system to be bled of any air prior to pressurisation or to lower the plungers.

The end block 12 has an hydraulic fluid passageway 50 extending horizontally therethrough, the inner_. end of which communicates with the bore 51 of a male joining element 14 identical to that previously described, whilst the outer end is arranged to connect to an hydraulic fluid supply line (not shown) .

Referring to Fig 7, each block 11 is provided with one or more ball locking wedge devices 53 in one of its side walls spaced along the length thereof, each device 53 comprising a movable steel ball 54 captively retained in a recessed opening 55 extending horizontally inwardly from the side wall 56 of the block 11, the opening 55, communicating with a vertical passageway 57 which is threaded for threadably receiving a grub screw 58 which can be axially adjusted to in turn vary the position of the ball 54. The ball 54 is arranged to move between a retracted position where the ball is housed wholly within the confines of the opening 55, and an extended position where a portion of the ball 54 projects beyond the side wall 56 and, when in use, makes frictional contact against a vertical wall 59 of the T- shape slot 60 formed in the press bed 61 (refer Fig 10) to thereby wedgingly secure the block 11 within its slot 60. The ball 54 is held against dislodgement by an outwardly convergent lip 62 surrounding the mouth of the opening 55. As shown in Fig 2, end block 12 can also be provided with a ball locking device 53. The embodiment illustrated in Fig 8 shows an hydraulic die lifter assembly 64 which is virtually identical to that of Fig 1, except the steel balls 20 are replaced by rollers 65. Those parts of the assembly 64 which correspond to those parts of the first embodiment bear the same reference numbers. The rollers 65 can be set at any desired angle and need not be parallel to the central longitudinal plane of the block 11 as shown in Fig 8.

Fig 10 of the drawings illustrates the blocks 11 located in the T-slots 60 of the press bed 61, one of the blocks 11 being shown in its pressurised condition with its rollers 65 supporting a die 67 in a raised position above the- bed 61 for ease of positioning or removal, the other with its rollers 65 retracted with the die 67 supported on the press bed.

It should of course be appreciated that the number of modular blocks 11 will vary according to the length of the press bed, with each of the blocks 11 being interlocked with an adjacent element 11 by means of the bayonet-cap type interconnection formed by the joining elements 14, 15. The end blocks 12, 13 will be respectively coupled to the extreme outer block elements 11 of the assembly.

In will of course be appreciated that the bayonet-cap type interconnection may be formed by having projections or lug portions provided within the female cavity of the female joining element, and appropriately shaped axial/ circumferential grooves or recesses on the outer surface of the male joining element.

A brief consideration of the above-described embodiment will indicate that the invention provides for a very simple and effective modular die lifter assembly which can be easily installed in existing press beds, and wherein each of the elements of the assembly can be very quickly and readily interconnected (or disassembled) .

Claims (16)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS

1. An improved hydraulic modular die or tool assembly comprising a plurality of die lifter modular blocks interconnectable in end-to-end contiguous relation to form a horizontal row, each said block having a top wall, a bottom wall, a pair of opposite parallel planar end walls and a pair of opposite parallel planar side walls, a fluid flow passageway extending longitudinally through said block, a plurality of spaced apart parallel bores extending vertically inwardly from said top wall and communicating with said passageway, plungers movable within said bores between retracted and extended positions, each said plunger carrying at its upper end a rotatable load bearing element, arranged so that upon admission of pressure fluid in said passageway, the plungers are moved to their extended positions wherein said load bearing elements project above the plane of said top wall to thereby support the die or tool in a raised position above said plane, wherein each said block has a male joining element integral with and projecting from one of its said end walls and a female joining element at its other said end wall arranged to co¬ operate with a male joining element of an adjacent said block, said male joining element having a bore extending therethrough co-axial with and joining said passageway, said male and female joining elements co-operating respectively with female and male joining elements of adjacent blocks for releasably lockingly engaging said blocks in said end-to-end relation, said blocks when so interconnected, having their passageways in fluid flow communication with one another, and sealing means for effecting a seal between mating surfaces of the interlocking male and female joining elements.

2. An improved hydraulic modular die or tool assembly accordingly to claim 1 wherein said male and female joining elements together form bayonet-cap type interconnection means.

3. An improved hydraulic modular die or tool assembly according to claim 2 wherein said male joining element comprises a planar lug axially spaced from said one of said end walls, said lug having a pair of diametrically opposed radially projecting lug portions arranged, to lockingly engage within lug receiving pockets in said cavity.

4, An improved hydraulic modular die or tool assembly according to claim 3 wherein the periphery of said lug is defined by a pair of opposed arcuate edge surfaces joined by a pair of opposed linear edge surfaces, said linear edge surfaces extending at right angles to the central longitudinal vertical plane of the block.

5. An improved hydraulic modular die or tool assembly accordingly to any one of claims 2 to 4 wherein said sealing means comprises a resilient O-ring located in an annular groove formed in the end face of said lug surrounding said bore, said O-ring, when said adjacent blocks are interconnected, being pressed against its resilience into sealing engagement with an end wall of said female cavity.

6. An improved hydraulic modular die or tool assembly according to any one claims 3 to 5 wherein said female joining element comprises walls defining a slotted opening extending inwardly from said other of said end walls, said opening being shaped and dimensioned so as to allow the insertion of said lug axially into the cavity only when said blocks are positioned at an angle of 90^* to one another, the walls defining said slotted opening connecting with a circular recessed portion co-axial with said passageway and having a axial depth which approximately equals the thickness of said lug, said lug receiving pockets being formed at diametrically opposed locations within said recessed portion.

7. An improved hydraulic modular die or tool assembly according to any one of the preceding claims wherein each said block is of rectangular cross-sectional shape.

8. An improved hydraulic modular die or tool assembly according to any one of the preceding claims wherein each said modular block has a width which is small relative to its length.

9. An improved hydraulic modular die or tool assembly according to any one of the preceding claims further comprising a pair of end blocks respectively interconnected to the outermost ones of said blocks, one of said end blocks being provided with a said male joining element for interlocking engagement with a said female joining element of one of said outermost blocks, the other said end block being provided with a said female joining element arranged to interlock with a male joining element on the other of' said outermost blocks.

10. An improved hydraulic modular die or tool assembly according to claim 8 wherein one of said end blocks comprises a pressure fluid inlet means connectable to a supply of pressure fluid, said other end block providing means for closing off said passageway.

11. An hydraulic die lifter module element comprising an elongate rectangular block having a planar upper wall, and a pair of opposite parallel planar end walls, a fluid flow passage way extending longitudinally through said block, a plurality of spaced apart parallel cylindrical bores extending vertically inwards from said upper wall and communicating with said passageway, plungers movable within said bores between retracted and extended positions, each said plunger carrying at its upper end a rotatable load bearing element, arranged so that upon admission of pressure fluid in said passageway, the plungers are moved to their extended positions wherein said load bearing elements project above the plane of said upper wall to thereby support the die or tool in a raised position above said plane, wherein each said block has a male joining element integral with and projecting from one of its said end walls and a female joining element formed at its other said end wall arranged to co-operate with a male joining element of an adjacent said block, said male joining element having a bore extending therethrough which is co-axial and joins with said passageway, said female joining element comprising walls defining a female cavity which fluidly communicates, centrally thereof, with said passageway, said joining elements constituting releasable interlocking means whereby said block can be interconnected end-to-end horizontally with an identical said block, the blocks when thus interconnected, having their passageways in fluid flow communication with one another, one of said joining elements including a sealing member for effecting a seal between mating surfaces of said one of said joining elements and a joining element of an identical block when interlocked therewith.

12. An hydraulic die lifter module element according to claim 10 wherein the male and female joining elements provide a bayonet-cap type interconnection.

13. An hydraulic die lifter module element according to claim 12 wherein said male joining element comprises a planar lug axially spaced from said one of said end walls, said lug having a pair of diametrically opposed curved lug portions arranged to be received in lug receiving pockets in a said female cavity, an annular groove formed in the end face of said lug and surrounding said bore, a resilient O-ring located in said groove so as to project axially beyond said end face so that when the joining elements are interlocked, said O-ring is compressed against its resilience into sealing engagement with an end wall of said female cavity.

14. An hydraulic die lifter module element according to claim 13 wherein said female cavity comprises walls defining a slotted opening extending inwardly from the other end wall of said block, said slotted opening communicating with a circular recessed portion having a diameter which is slightly greater than the maximum transverse dimension of said lug, the depth of said recess portion being approximately equal to the thickness of said lug, said lug receiving pockets being formed at diametrically opposed locations on the said recessed portion.

15. An hydraulic die or tool lifter assembly substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings .

16. An hydraulic die lifter module element substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.