US3476371A - Apparatus for use in effecting controlled quenching of metal in bar form - Google Patents

Apparatus for use in effecting controlled quenching of metal in bar form Download PDF

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US3476371A
US3476371A US612178A US3476371DA US3476371A US 3476371 A US3476371 A US 3476371A US 612178 A US612178 A US 612178A US 3476371D A US3476371D A US 3476371DA US 3476371 A US3476371 A US 3476371A
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bar
quenching
bank
bars
switch
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US612178A
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Alfred Travis
Philip Croft
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EXECUTORS OF JAMES MILLS Ltd
MILLS JAMES Ltd
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MILLS JAMES Ltd
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/62—Quenching devices
    • C21D1/63—Quenching devices for bath quenching
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B43/00—Cooling beds, whether stationary or moving; Means specially associated with cooling beds, e.g. for braking work or for transferring it to or from the bed

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  • This invention relates to a new or improved apparatus for use in effecting the controlled quenching of metal in bar form.
  • the invention has been developed specifically in connection with the method of quench hardening certain classes of steel, in accordance with the invention the subject of our prior Patent No. 3,111,- 436, the apparatus the subject of the present invention is considered to be of general application to the controlled quenching of any steel, as well as of other metals in bar form, using quenching baths of water, or of oil or other media in place of water.
  • the present invention has for its object the provision of a new or improved apparatus for effecting in an automatic manner the controlled quenching of steel and other metal in bar form, and which takes into consideration the foregoing requirements.
  • Bar supporting means movable between three different positions, namely a bar receiving position, a bar immersion position in which the bar is immersed within the quenching bath, and a bar discharge position, in which the bar is discharged from said supporting means,
  • Control means responsive to the temperature of each bar, arranged to initiate the movement of the bar supporting means after a bar has been fed thereto and into the bar immersion position to immerse the bar within the quenching bath when the temperature of the hot bar has fallen to a value corresponding to the required bar quenching temperature or range of temperature,
  • a timing device arranged to control the duration of immersion within the bath of the bars by the supporting means
  • Said bar supporting means being arranged to effect discharge of the quenched bars therefrom after their immersion in the quenching bath for the required period of time.
  • the bar reject means operated by said temperature responsive control means may be arranged to discharge bars at a temperature below the designed temperature without the bars so discharged being supported at all by the bar supporting means, but preferably each bar would be fed to the supporting means and the control means would be arranged so as to be responsive to the bar temperature when the bar is on the supporting means.
  • the bar receiving bank comprises a series of bar locations such as pockets spaced apart from one another in a direction transverse to the direction of bar feed to the bank
  • the means for feeding the advancing bars to the bank comprises a bar transfer device responsive to the presence of a bar in the rearrnost of the succession of bar occupied bank locations, so as to deposit the next successively advancing bar in the location next in rear (in the direction of bar advancement) to the location already occupied by the bar last fed thereto.
  • the bar supporting means comprises two sets of bar retaining jaws relatively movable under the control of both the temperature responsive control means as well as under the overriding control of the timing device between a closed bar retaining position and an open bar receiving and discharge position, and the bar supporting means as a whole may be movable under the control of said control means between two raised positions in each of which the jaws are in an open position, namely a bar receiving position, in which the opening presented by the two sets of jaws is directed toward the bank, and a bar discharge position in which the jaw opening is directed towards a bar collecting trough or other collecting device to which the bars are discharged in a direction away from the bank, the bar supporting means being also adapted with the jaws in the closed position to be displaced into and out of a lower quenching position by the respective operation of the temperature responsive control means and the timing device.
  • the bar transfer device may comprise a bar feeding element embodying a bar supporting part and a bar engaging part, which two parts are spaced relatively apart in a direction transverse to the direction of bar feed to the bank, by a distance corresponding to the transverse spacing between adjacent bar locations, the bar engaging part of the feeding element being adapted to engage and thus to sense a bar in an already occupied location and there being means for displacing the bar feeding element in an orbital path to deposit the fed bar into an unoccupied location immediately in rear of the bar occupied location sensed by said bar engaging part, said bar feeding element being driven in its orbital path through a slippable clutch adapted to permit of the orbital movement of the bar feeding element, varying in accordance with the extent of occupation of the bank, as determined by the sensing action of the bar engaging part of the bar feeding element.
  • the means for feeding the bars successively from the bank to the bar supporting means comprises a walking beam element, the operation of which is actuated by a device responsive to the presence or absence of a bar on the bar supporting means after the latter has returned to its bar receiving position, the arrangement being such that the walking beam operates to feed a bar to the supporting means when empty, each time this is in its bar receiving position and simultaneously feeds by one step, i.e. one location in a forward direction any bars which have accumulated on the bank successively behind the foremost location previously containing the bar in course of being fed by the walking beam to the supporting means.
  • the apparatus includes bent bar actuated means responsive to failure of the jaws of the supporting means to move relatively into their closed position, as a result of more than a permissible departure of the bar from straight configuration, said bent bar actuated means being adapted to displace the bar supporting means into the bar discharge position, and to effect relative movement of the jaws into their open position to discharge the so rejected bar without immersion within the quenching bath, and there being means responsive to the operation of said bent bar actuated means for diverting said discharged bent bar to a discharge position other than the position to which the quenched bars are discharged.
  • FIGURE 1 is a plan view of one form of apparatus embodying the present invention.
  • FIGURES 2 and 2A are plan views to an enlarged scale of certain portions of the apparatus as depicted in FIGURE 1.
  • FIGURE 3 is a front elevation of part of the apparatus as depicted in FIGURE 2.
  • FIGURE 4 is a crosssectional view of the apparatus looking in a direction from right to left in FIGURE 1.
  • FIGURE 5 is a cross-sectional view to an enlarged scale of part of the apparatus depicted in FIGURE 4.
  • FIGURES 6, 7, and 7A are respectively diagrams of the pneumatic circuit and the electric circuit constituting the control means of the apparatus depicted in FIG- URES 1 to 5.
  • FIGURES 1 to 5 of the drawings the mechanical construction of the apparatus and the manner in which the various parts coact mechanically with one another will firstly be described, before explaining completely the sequence of operations and the manner in which these are controlled by the pneumatic and electric circuits respectively depicted in FIGURES 6, 7 and 7A.
  • the apparatus illustrated in the drawing comprises a bar receiving bank 10 and means generally indicated at 11 for feeding to the bank 10 a succession of hot rolled bars directed from the bar or rod mill, which may be of conventional form and is not illustrated.
  • the bars are advanced from the mill over a bar supporting table 12 adjacent to which is a hot bed 13 of conventional form with a gate 14 at the forward end of the table 12.
  • the gate 14 is normally in an open position, but under the control of pneumatic ram P1 is displaced into a closed position by the advance of a bar completely past the gate, so as to prevent more than a single bar at a time being fed past the gate.
  • the means 11 for feeding the hot bars to the bank 10 comprise a series of power driven bar feeding rollers 15 which are arranged to engage only with the underside of the bar, so as to advance this in the direction of the arrow 16 to the end stop 17 aligned with the row of feed rollers 15.
  • the arrangement is such that the bars are advanced successively by the rollers to a position adjacent one side, namely the rear side 10:: see FIG. 4 of the bank 10, and the latter is of elongated configuration, so as to have a length corresponding to the length of the longest bar designed to be fed to the apparatus from the mill.
  • the means 11 for feeding the bars successively to the bank 10 further comprise a bar transfer device consisting of a plurality of bar feeding elements 18, each comprising a bar supporting part 19, together with a bar engaging part 20 (see FIGURE 4).
  • Each of these bar feeding elements 18 may, as shown in FIGURE 4, be formed of rod to provide a bar supporting part 19 in the form of a V notch adjacent to which, but on the forward side in the direction of bar feed, the bar engaging part 20 is provided.
  • a number of these bar feeding elements 18 are provided spaced apart along the length of the bank 10, and are carried upon a supporting tube 21 which may be fixed or preferably rotatably mounted in bearing blocks 22 in turn carried on the free end portion of one of a series of levers 23, the opposite end of each lever being pivoted to the upper end of fulcrum link 24, the lower end of which is hinged to the base 25 of the apparatus.
  • the lever 23 intermediate its two ends is pivoted at 26 to piston rod 27 connected to the piston of pneumatic lifting ram P2, which serves to lift the bar feeding elements 18 prior to their movement in a lefthand direction in FIG. 4, to transfer the bar towards the quenching bath.
  • This ram P2 is pivoted at 28 to the middle part of substantially vertical control link 29, the upper end of which is pivoted to one end of intermediate link 30, the other end of which is pivoted at pivot 26 to lever 23.
  • control link 29 is mounted on rock shaft 31, which is driven through a slippable clutch 32 from bar feeding element pneumatic ram P3, fulcrumed at 33 to base 25.
  • This ram P3 serves to transfer in a substantially horizontal direction, i.e. from right to left in FIGURE 4, the bars in a direction towards the quenching bath and the provision of the slippable clutch 32, permits of the amplitude of bar feeding movement of the bar feeding element 18, which movement is in a direction transverse to the length of the bank 10, varying in the manner later described in accordance with the extent of occupation of the bank 10 by bars previously fed thereto, with the piston of ram P3 each time completing its full stroke.
  • the movement of the bar feeding element 18 is controlled by the lifting ram P2 and the transfer ram P3, respectively operating to displace the bar feeding element in a substantially vertical and a substantially horizontal direction, so that the bar feeding element 18 in the course of its feeding and return stroke performs an orbital movement.
  • the bar receiving bank 10 is formed by a large number of bank plates 34 arranged in parallel relationship but spaced apart in a direction along the length of the bank 10, and the upper edge of each of these plates 34 is of saw tooth configuration, so as to provide a series of upwardly directed substantially V-shaped pockets 3S spaced apart from one another in a direction perpendicularly transverse o the length f e ba with a h or the pockets 35 of one bank plate 34 aligned in a direction of bank length, with one of the notches of each of the other plates 34.
  • the bank comprises a series of pocket like bar locations constituted by the notches 35 and spaced apart from one another in a direction transverse to the direction of arrow 16 of bar feed to the bank.
  • the arrangement permits of the accumulation on the bank of a variable number of bars 36 within the overall capacity of the bank, so that it is not required precisely to co-ordinate the rate of discharge of the bars from the mill with the feeding of the bars into the quenching bath, the provision of the bank 10 providing for the necessary flexibility in operation of the apparatus without it being normally necessary to make use of the hot bed 13.
  • a quenching bath 37 in the form of a trough which extends for the full length of the bank, but below the level thereof, and it is adapted to contain the required quenching medium which in the preferred application of the invention relating to the aforementioned prior patent, is water.
  • This bath 37 may be provided with water supply means and a discharge weir, not shown, with provision for a constant flow of water into and out of the quenching bath, so as to maintain this at a predetermined temperature or temperature range, despite the heat supplied thereto from the bars during quenching.
  • bar supporting means 38 for advancing the bar from the bank into the quenching bath, and for supporting the bar therein, as well as for discharging the bar from the bath after quenching.
  • This bar supporting means comprises two sets of bar retaining jaws 39, 40, which are relatively movable between an open bar receiving discharge position in which the relative disposition of the two sets of jaws is shown in full outline in FIGURE 5, and a closed bar retaining position corresponding to the position of the parts when immersed within the water 41 in the bath 37.
  • the jaws 39 are each of notch like configuration, and the jaws 40 are constituted by a series of arms.
  • the jaws 39 are carried upon a main jaw shaft 42, supported for rotational movement on fixed fulcrums 43 carried on part of the base 25, and the jaw arms 40 are carried on a jaw spindle 44 which extends parallel to the shaft 42, and which is rotatably supported from the jaws 39.
  • the spindle 44 at the end thereof which is nearest to the table 12 has mounted thereon a follower roller 45, which engages with wedge member 46, which is mounted on the adjacent end of shaft 42, and along the length of which it is free to slide.
  • wedge member 46 is pivoted at 46a to an upstanding part of bracket 47 connected to collet 48 which is also axially slidable along the length of shaft 42.
  • collet 48 is grooved at 4811 to receive the abutment pins 48b carried on yoke 48c mounted on vertical pivot 48d, and connected through link 48e to the I piston rod of pneumatically operated jaw opening and closing ram P7.
  • the arrangement is such that when the piston rod of ram P7 is displaced, the collet 48 and bracket 47 and wedge member 46 connected to the bracket, are all slidden in a direction along the length of shaft 42 relative to shaft 44, so as by the engagement of wedge member 46 with'follower roller 45 to effect oscillatory movement of spindle 44 relative to jaw shaft 42, and thus to displace the movable jaw arms 40 relative to the jaws 39, between their open and closed positions.
  • the wedge member 46 is adjustable about its pivot 46a relative to bracket 47, so as to vary the inclination of its wedge face 46b to the adjacent axis of spindle 44, and thus to vary for a given axial displacement of wedge 46 by ram P7 of the rotational movement of spindle 44 and associated jaw arms 40, in accordance with the diameter of the bar to be quenched, the greater rotational movement of the jaw arms 40 from the open to the closed position being necessary in the case of the small diameter bars than with large diameter bars to effectively retain the small diameter bars within the jaws, it being understood that in the case of larger diameter bars there is a limit to the closing movement of the jaw arms 40 by reason of them engaging with the bars within the jaw notches 39.
  • bracket 47 carries adjusting screw 47a, the free end of which engages with adjacent face of wedge member 46, so as to swing this about pivot 46a, while the wedge member is further provided with locking screw 46c carried on an adjacent part of bracket 47, which extends through an arcuate slot in the wedge member.
  • the bar supporting means 38 is movable between an upper bar receiving position 38a in FIGURE 5, in which it is disposed adjacent the discharge side 10b of bank 10, so as to be adapted to receive a bar therefrom, and a lower quenching position 38b in which the two sets of jaws are immersed Within the water or other quenching medium.
  • the said movement in each direction is through an intermediate position 38c, which prior to quenching constitutes a holding position at which the temperature of the bar is being determined prior to quenching, and which postion 380 after quenching is the bar discharge position.
  • Means are provided for feeding the bars 36 from the bank 10 to the bar supporting means 38 when this is in the bar receiving position 38a, in such a manner that the bars are fed successively thereto in the same order as that in which they are advanced in the heated state to the bank.
  • Such bar feeding means comprises a walking beam device 49 constituted by a ,series of bar feeding strips 50, there being a strip disposed in the space between each pair of bank plates 34, each strip 50 being of saw tooth configuration at its upper edge, so that each strip 50 is formed with a series of bar feed edges 51 which slope downwardly and forwardly in the direction of bar feed, each of these bar feed edges 51 having a pitch or relative spacing which is the same as that of the bar location pockets 35 of each plate 34.
  • Each of the strips 50 is carried on a dependent walking beam arm 52 supported from base 25 by fulcrum link 53, and the lower part of each arm 52 is connected by walking beam drive arm 54 to walking beam driving mechanism 55 of conventional form, and operated by a pair of walking beam pneumatic rams P4, the operation of which, as later described herein, is controlled by the particular disposition of the bar supporting means 38 in its bar receiving position 38a with the two sets of jaws open.
  • Fulcrum link 53 extends substantially parallel to drive arm'54, and the arrangement is accordingly such that the walking beam arm 52 with its associated strips 50 is constrained to move in a substantially vertical direction between its lower inoperative position depicted at 49a in FIG. 5, and its upper bar feeding position depicted at 49b in that figure.
  • each bar feed edge 51 of each strip 50 is disposed in vertical alignment with bar receiving corner 35a of each notch or pocket 35, with each bar feed edge 51 also extending beneath that crest 56 of each bank plate 54, which is on the forward side of the aforesaid corner 35a.
  • each bar within each of the notches or pockets 35 will be raised by engagement with the adjacent bar feed edge 51 on strips 50, clear of that crest 56 which is on the immediate forward side of the bar concerned, so that the latter rolls gravitationally downwardly and forwardly of the so engaged bar feed edge 51 past the aforementioned adjacent notch into the forwardly adjacent corner 50a of the associated notch 50b of strip 50; i.e. bar originally at the position 36a in FIG.
  • each of the bars 36 within the pockets 35 are simultaneously advanced in a direction towards the discharge side 10b of the bank, i.e. from right to left in FIGURE 4, by a distance corresponding to the pitch distance of the bar locations 35.
  • the bar supporting means 38 must be in the upper bar receiving position 38a; there must be a bar in the foremost of the locations 35, namely, in location 3511 which is nearest to the discharge side 1015 of the bank; also the transfer device must be in its retracted position or on its return stroke towards such position. Assuming that the foregoing conditions are fulfilled, a bar previously within the foremost location 35b will slide down the foremost of the walking beam edges 51 as well as sliding down the adjacent downwardly sloping discharge nose 57 of the bank plates 34, so as to be received within the open jaws of the supporting means 38 in its bar receiving position 38a.
  • the jaws 40 will now move into the closed position with the walking beam strips 50 still in their raised position in which they will remain until as later described, the bar supporting means 38 commences to travel towards the intermediate position 38d (see FIGURE 5).
  • the walking beam strips 50 will now move downwardly so as to deposit the next successively advancing bar into pocket or location 35b, after which the walking beam strips will return to their initial position ready to again deposit the next successively advancing bar into pocket 35b.
  • the walking beam device 49 advances the several bars 36 in a direction towards the bar supporting means 38, in such a manner that the bars are fed successively to the bar supporting means 38 in the same order as that in which they are advanced in the heated state to the bank. It is thereby possible by suitable control of the rolling mill temperature for the bars to be advanced by the bar feeding means 11 and bar feeding elements 18 to the bank 10 at a temperature such that by the time each bar has reached the foremost bank location 3512 and the bar supporting means 38 is in its bar receiving position, the bar will have cooled to a temperature corresponding to the required temperature at which the bar is to enter the quenching bath. At the same time the step-wise advancement of the bars across the bank 10 provide for a slow cooling, i.e. air cooling, of the bars prior to quenching, which is an essential feature of the invention the subject of the prior patent.
  • a slow cooling i.e. air cooling
  • the bar supporting means 38 are displaced from the bar receiving position 380: to the intermediate or centre position 380 by means of pneumatic ram P5, and are displaced from the intemediate or centre position 38c to the immersion position 38b within quenching bath 37, by a further pneumatic ra n P8, constituting a quenching ram,
  • these two ams P5 and P8 are arranged in tandem, so as to constitute a double cylinder 58 formed as one member, and having two pistons, the piston rods 59, 59a of which relate respectively to rams P5 and P8.
  • Piston rod 59 see FIG. 4, is fixed to the base 25, with the cylinder 58 being vertically movable and piston rod 59a is connected to vertically extending rack 60, which meshes with rack pinion 61 mounted on main jaw shaft 42.
  • the arrangement is such that when the air pressure is supplied merely to ram PS, the cylinder 58 and piston rod 59a are displaced vertically without relative movement therebetween by an amount such as to rotate shaft 42 by a distance sufiicient to displace the bar supporting means 38 from its bar receiving position 38a to its intermediate position 38c, while when the air pressure is supplied to ram P8 the associated piston rod 59a is displaced relative to cylinder 58 in the same direction by a further distance to effect further rotation of shaft 42, and thus displace the bar supporting means 38 from its intermediate position 380 to its quenching position 38b.
  • the bath 37 at the side thereof furthest from the apparatus is provided with a bar discharging table 62, adapted to receive bars discharged thereon from the bar supporting means 38, when in the intermediate position 38c, to which the bar is raised after quenching, before the jaws 39 open to discharge the quenched bar therefrom.
  • This table 62 slopes downwardly away from bath 37 to a quenched bar receiving trough 63, in which the quenched bars accumulate, from which they are removed periodically as convenient, and in which trough 63 the bars may be allowed to remain so as to affect final slow air cooling in which evening up occurs of the temperature difference between the surface layers and the core of each bar following the interuption of the water quenching, which is a further essential feature of the method of quench hardening the subject of the prior patent.
  • the bar reject means arranged to effect discharge without quenching of any bars at a temperature below the requisite temperature prior to quenching, comprise the provision of a series of deflector arms 64 supported at one end on bar deflector shaft 65, with the arms 64 spaced at intervals therealong, the shaft 65 being pivotable under the control of a pair of bar reject pneumatic rams P6, between an upstanding position as shown in full outline in FIGURE 4, and a horizontal reject position depicted in dashed outline in FIGURE 4, in which the deflector arms 64 lie across the mouth of quenched bar receiving trough 63, so as positively to prevent the discharge of unquenched bars thereto, and instead to deflect such unquenched bars into reject bar receiving trough 66, disposed, as shown in FIGURE 4, beyond the outer side of trough 63.
  • Such reject means also serve to deflect into trough 66 any non-straight bars, in manner later explained, so that trough 66 receives all bars which are rejected either by reason of being of insufficiently straight configuration, or being at a temperature too low before quenching.
  • FIGURE 6 of the drawing depicted the pneumatic circuit for operating the various pneumatic rams, P1 to P8 inclusive, the function of which has already been described.
  • Each of these rams is a double acting ram, and each ram P1 to P8 is respectively controlled by solenoid operated air valve V1 to V8, each valve being connected to opposite ends of the associated ram by a pair of air lines AL, with each an valve being provided with the usual supply line SL, connected to air storage tank AST having main air suppl line MSL.
  • Each air valve is further provided with exhaust air line EL.
  • each of the several rams P1 to P8 is depicted with its associated iston rod PR, in the position occupied when the solenoid controlling each of the air valves V1 to V8 inclusive is energised.
  • the piston rods thereof are retracted, while in the case of the remaining rams, when their respective solenoids are energised, the piston rods are advanced as shown on the drawing.
  • the solenoid for operating each of the air valves V1 to V8 inclusive is respectively' controlled by contactor coil S1 to S8 inclusive, and which are embodied in the electric circuit depicted in FIGURES 7 and 7A, forming with the pneumatic circuit for operating the rams the control means for the apparatus, depicted in FIGURES 1 to 5.
  • each relay contact r1 is controlled by the one contactor coil R1.
  • some of the contactor coils "have more than one set of relay contacts. In respect of each relay contact when their corresponding coils are energised, such contacts, if depicted closed, will open, and if depicted open in FIGS. 7 and 7A, will then close.
  • the circuit embodies a pyrometer 67, which is a known form of optical pyrometer, mounted, as shown in FIGURE 1, at a position so as to be sensitive to' the temperature of the bar about to be quenched, when this is in the mid position 38c.
  • the pyrometer is provided with three control switch contacts Tr, Ta'l and Ta1(i), the opening and closing of which is in the known manner forming no part of this invention, under the control of the temperature sensitive element of the pyrometer, itself responsive to the temperature of the bar when in the mid position 38c.
  • the circuit further includes a timer motor 68 of known form, which is in circuit with solenoid contactor coil S8 controlling ram P8, and which can be driven for an adjustable period of time thruogh electrically rotated timer clutch 69.
  • the arrangement is such that after the timer motor has operated for the predetermined period, the contactor coil S8 is de-energised to de-energise the associated solenoid controlling air valve V8, associated with pneumatic ram P8, so as then to effect retraction of the now quenched bar from the quenching bath 37.
  • the circuit is energised from the main supply leads 70, and the connection of these to the various switches and contactor coils will be apparent from the drawing.
  • closing start switch 71 provided on an operating panel 72 (see FIG. 1).
  • the effect of closing start switch 71 is to energise contactor coils R3 and R30, to close the illustrated open relay contacts r3 and r3a, so as to effect a preliminary energisation of certain parts of the circuit.
  • the bar is advanced along the bank 10 by the feeding means 11, power driven continuously independently of the control of the electric circuit, so that the bar is advanced to end stop 17, adjacent to the lower side of which is disposed flag switch lsl, having a detent engaged by the end of the bar as it reaches stop 17, so as to close this flag switch and energise contactor coil R1, to close the associated switch contacts r1.
  • the effect of this is to energise the contactor coils S1 and S2, closing their associated contacts s1 and s2, which are respectively associated with pneumatic rams P1 and P2.
  • contactor coil S3 is energised. Its contact s3 when closed at once actuates the solenoid controlling transfer ram P3, which now displaces the feeding means 18 in a direction to transfer the bars to the vacant pocket 35 of bank 10, which is closest to the quenching bath 37.
  • the switch ls2a is in series with the solenoid contacts 52, and since contacts r1 have previously opened by d e-energisation of coil R1 contactor coil S2 is now de-energised, so that each of its associated contacts s2 open to retract the piston rod or ram P2, and lower the feeding means 18 to deposit the bar within the aforementioned vacant notch 35 nearest bar 37 and at the same time to thus open switch [s3 responsive to the vertical position of feeding means 18.
  • a spring loaded normally closed switch ls3a In association with the piston rod of ram P2, is a spring loaded normally closed switch ls3a, the detent of which is engaged to open switch ls3a only when the piston rod of ram P2 is retracted, i.e. to a position corresponding to the lowered position of feeding means 18.
  • switch ls3 has already opened, the effect of opening switch ls3a is to de-energise contactor coil S3 controlling transfer ram P3, the piston rod of which is retracted to displace the feeding means 18 already in a lowered position, in a righthand direction in FIG. 4, leaving the bar deposited in the above mentioned vacant pocket 35.
  • the feeding means As the feeding means completes its return movement to its initial inoperative position below feeding rollers 15, i.e. below its full line position in FIG. 4, it opens the normally closed swtch lsla diagramatically shown in FIG. 4, to de-energise contactor coil S1 and thus advance the piston of its associated ram P1 to open gate14, to permit of the advancement of a second bar, with the feeding means 18 ready to engage with it.
  • Contact s3a is in series with switch ls4a, which is closed so long as the bar jaws 39, 40 are in their top position 38a. Also in series with the switch s3a is switch ls4b, which is closed by the presence of a bar in the foremost pocket 35a.
  • a spring loaded normally open detent operated switch ls9 in circuit with contactor coil R4, which is closed by the above mentioned movement of walking beam 49 into its raised position, so as to energise coil R4 of relay contact R4, which is in series with contactor coil S7 controlling jaw opening and closing ram P7, and is also in series with normally open timer switch s4a closed by the energisation of contactor coil S4, but incorporating an adjustable time delay device of known form.
  • the object of this is to allow time for the foremost bar discharged to the jaws 39, 40 by the walking beam, to reach these jaws before coil S7 is energised to displace ram P7 in a direction to close the jaws 39, 49 after the reception of the bar therein. 7
  • Contactor coil S7 also controls a normally open switch s7a provided with a timing device, so as when energised to close s7a after a time interval long enough to allow for full closure of the jaws 39, 40, before by such closure of switch .s'7a to energise contactor coil 85 which through its relay contact s controls the solenoid operating ram P5, which lowers the closed jaws from the top position 38a to the mid or intermediate position 380.
  • Contactor coil S5 also controls timer start switch s5t, which is a double pole switch in circuit with step down transformer 73, the output of which is connected to the timer motor 68, so as to start the motor, but leaving the clutch 69 driven from the motor still disengaged.
  • timer start switch s5t is a double pole switch in circuit with step down transformer 73, the output of which is connected to the timer motor 68, so as to start the motor, but leaving the clutch 69 driven from the motor still disengaged.
  • Contactor coil S5 also operates pyrometer relay sSp, so as when energised to close the relay contacts and thus energise the relay coil CIT, to close the associated relay contact cit to supply current to pyrometer 67.
  • This pyrometer through a normally closed manually operable pyrometer selector switch PS8, is in circuit through normally closed relay s81 of contactor coil S8, with the contactor coil 86 which controls the solenoid actuating the bar reject ram P6.
  • the arrangement is such that when the solenoid controlling this ram P6 is de-encrgised, the bar deflector arms 64 are in the upstanding or bar acceptance position permitting of controlled quenching.
  • the pyrometer 67 incorporates two series of control switch contacts, arranged in parallel, namely switch contact Tr, which is in series with contactor coil S6 and arranged in parallel with the two in series switch contacts Tal and Ta1(i), which are themselves in series with the contactor coil S8, which coil controls the solenoid operating ram P8 for lowering the jaws 39, 40 from the mid position 38c to the quenching position 38b, and from this position back to the mid position 38c.
  • Pyrometer switch contact Tr isclosed when the bar temperature as measured by the pyrometer is below the minimum acceptable temperature for quenching, so as then to energise contactor coil S6, the contact Tr being open when the bar temperature is at or above the minimum acceptable temperature.
  • Switch contact Ta1(i) is normally closed, but opens when the bar temperature as measured by the pyrometer is above the maximum acceptable temperature for quenching, the effect of opening this contact being to prevent contactor coil S8 being energised until the bar temperature has fallen to the maximum acceptable temperature.
  • Pyrometer switch contact T01 is a normally open contact, which closes under the control of the pyrometer when the bar temperature approaches the minimum acceptable temperature for quenching, so as with Ta1(i) already closed then to effect energisation of contactor coil S8.
  • the pyrometer includes in the known manner, forming no part of this invention, provision for adjusting the temperature at which the three switch contacts Tr, Tal and Ta1(i) respectively open and close according to the metallurgical characteristics of the bar and the required heat treatment.
  • switch ls7 In association with deflector arms 64 is normally closed spring loaded switch ls7, the detent of which is engaged by deflector arm 64 when in the horizontal bar rejecting position.
  • the switch is in series with contactor coil S7 controlling the jaw opening and closing ram P7, and insofar as relay r4 has again opened, by reasons of the opening of switch ls9, consequent on the lowering of walking beam 49, the effect of opening switch 157 is to deenergise contactor coil S7, so that the piston rod of ram P7 retracts to open the jaws 39 and 40, and discharge the bar at the unduly low temperature into the reject trough 66.
  • switch Ta1( i) will open, closing when the bar temperature falls to maximum permissible quenching temperature, but with switch contact Tal as yet remaining open until the minimum value of this temperature range is approached, so as then to close and energise contactor coil S8 to thereby energise the solenoid which controls rarn P8, and thus to advance the still closed jaws and bar therewithin from the mid position 38c to the quenching position 38b, and immerse the bar within the quenching bath.
  • the driven member of timer clutch 69 is connected through a driven shaft, which for convenience in the layout of the circuit diagram is diagrammatically indicated by the broken non-straight line 75, and the output end of this rotatable shaft 75 is connected to a rotary quench time contact Qtc, which is a normally closed switch in series with relay contacts r3a and relay s8 of contactor coil S8.
  • contactor coil R3a is energised, so long as start switch 71 is closed, the relay r3a is closed and relay s8 has already been closed by the previous energisation of coil S8 by the operation of the pyrometer 67, in closing its contact Tal.
  • One of the relay contacts of coil S7 namely contact s7b is in series with contactor coil SSA, relay contact of which s5a is through the at present closed relay s5 in series with contactor coil S5, whose associated time delay switch s7a has now under the control of its timing device again opened, following de-energisation of associated coil S7.
  • the elfect of opening relay s5a is to de-energise coil S5 and its associated solenoid to advance the piston rod of the associated ram P5 and thus return the jaws 39, 40 to their upper position 38a, ready to receive a further bar.
  • Switch ls4b will, of course, have already been closed by the feeding of a second bar to the foremost pocket 35a when the walking beam performed its cycle of operations preparatory to the quenching cycle just described, it being understood that concurrently with the removal of a bar from the foremost pocket 35a and its delivered to the open jaws in their top position 38a, a second bar will have been delivered to pocket 35a, so as to reclose switch ls4b.
  • each of the solenoid controlling contactor coils S1 to S8 inclusive is provided with normally open manually controlled press button switches mounted on switch panel 72, these switches being respectively designated msl to ms8 inclusive, and enabling any one of the corresponding solenoids and thus the corresponding rams P1 to P8 inclusive being manually controlled, egg. in testing particular sections of the apparatus.
  • a jaw full closed switch ls10 in association with the movable jaw shaft 40 is a jaw full closed switch ls10, which is open when the jaws 39, 40 are fully closed, but otherwise is in the closed position, and in particular is closed when the jaws fail fully to close, despite closure movement of the jaw shaft 44, e.g. by reason of a bar to be quenched being bent by more than an acceptable amount.
  • Switch ls10 is in series with relays s5 and r4 of contactor coils S5 and R4 respectively, so that when each of these coils is energised prior to the discharge of a bar to the at present open jaws at the upper position 38a, coil R5 is energised.
  • the latter is energised by the closure of switch ls9 when the walking beam completes its movement to deliver a bar to the at present open jaws in the upper position 38a after which coil S5 is energised as earlier explained, to close its above mentioned relay contact s5, and effect displacement of the jaws from the top to the mid position.
  • contactor coil R5 will now be energised, so as to open its relay r5p, which is in series with the above mentioned pyrometer switch Ta1, and to close its relay contact r5l in series with contactor coil S6.
  • the effect of the foregoing is respectively to prevent the pyrometer when the bar is at the correct temperature, from energising coil S8 and to energise the contactor coil S6, so as, as earlier explained, to effect displacement of the bar deflector arms 64 into their horizontal bar rejecting position.
  • the circuit includes two contactor coils CIT and CIR respectively referred to as instrument timerco'ils and instrument relay coils, which respectively control relay contacts cit(a:) and cit, and the two relay contacts cir.
  • Relay contacts cit(a) embodies a time delay which permits of the contact closing after a predetermined time interval, and is in series with one of the two relay contacts air, and through this with the above mentioned switches of the pyrometer 67.
  • Relay contact cit is in series with the other relay contacts air, and together are in parallel with relay contacts s6, s8 controlled by contactor coils S6 and S8, each of which last mentioned relay contacts are in parallel with one another, while being in circuit with instrument relay CIR.
  • the re-energisation of the pyrometer is effected by the re-energisation of contactor coil S5, which as earlier described closes relay sp to re-energise instrument timer coil CIT and thus close the associated two relay contacts cit(a) and cit, and as the relay contact air in series with cit(a) has already been closed by the de-energisation of instrument relay coil CIR, following the de-energisation of coil 55, the circuit is now in a position to allow the pyrometer to repeat its above described temperature control operation.
  • the reason for making relay contact cit(a) a time delay contact is to allow time for the pyrometer to respond after the advancement of a bar into the mid position 38c following the energisation of contactor coil S5.
  • a pair of pneumatic balance cylinders BC are provided for balancing out the weight of the moving parts of the bar feeding elements 18 and associated mechanism, both of these being depicted in FIG. 6, and one of these being shown in FIG. 4, each cylinder being centrally trunnioned at 77 to base 25, and having the free end of the piston rod 78 fulcrummed to arm 79 connected to rock shaft 31, to which is connected to lower end of vertical link 29.
  • bar supporting means movable between three different positions, namely a bar receiving position, a bar immersion position in which the bar is immersed within the quenching bath, and a bar discharge posi tion, in which the bar is discharged from said sup porting means,
  • a controlling device responsive to the temperature of each bar, arranged to initiate the movement of the bar supporting means after a bar has been fed thereto, into the bar immersion position to immerse the bar within the quenching bath when the temperature of the hot bar has fallen to a value corresponding to the required bar quenching temperature or range of temperature,
  • the bar receiving bank comprises a series of bar locations spaced apart from one another in a direction transverse to the direction of bar feed to the bank
  • the means for feeding the advancing bars to the bank comprises a bar transfer device responsive to the presence of a bar in the rearmost of the succession of bar occupied bank locations, so as to deposit the next successively advancing bar in the location next in rear (in the direction of bar advancement) to the location already occupied by the bar last fed thereto.
  • the bar transfer device comprises a bar feeding element embodying a bar supporting part and a bar engaging part, which two parts are spaced relatively apart in a direction transverse to the direction or bar feed to the bank, by a distance corresponding to the transverse spacing between adjacent bar locations, the bar engaging part of the feeding element being adapted to engage and thus to sense a bar in an already occupied location and there be'ing means for displacing the bar feeding element in an orbital path to deposit the fed bar into an unoccupied location immediately in rear of the bar occupied location sensed by said bar engaging part, said bar feeding element being driven in its orbital path through a slippable clutch adapted to permit of the orbital movement of the bar feeding element, varying in accordance with the extent of occupation of the bank, as determined by the sensing action of the bar engaging part of the bar feeding element.
  • the bar supporting means comprises two sets of bar retaining jaws relatively movable under the control of both the temperature responsive controlling device as well as under the control of the timing device between a closed bar retaining position and an open bar receiving and discharge position.
  • Apparatus according to claim 4 characterised in that the bar supporting means as a whole is movable under the control of said temperature responsive controlling device and timing device between two raised positions, namely a bar receiving position, in which the opening presented by the two sets of jaws is in the one case, namely the bar receiving postiion, directed towards the bank, and in the other case, namely the bar discharge position, directed towards a bar collecting trough or other collecting element to which the bars are discharged in a direction away from the bank, the bar supporting means being also adapted with the jaws in the closed position to be displaced into and out of a lower quenching position by the respective operation of the temperature responsive controlling device and the timing device.
  • the means for feeding the bars successively from the bank to the bar supporting means comprises a walking beam device, the operation of which is actuated by means responsive to the presence or absence of a bar on the bar supporting means when in its bar receiving position, the arrangement being such that the walking beam operates to feed a bar to the supporting means when empty, each time this is in its bar receiving position and simultaneously feeds by one step, i.e. one location, in a forward direction any bars which have accumulated on the bank successively behind the foremost location previously containing the bar in course of being fed by the walking beam to the supporting means.
  • Apparatus according to claim 1 characterised in the provision of reject means responsive to failure of the jaws of the supporting means to move relatively into their closed position, as a result of more than a permissible departure of the bar from straight configuration, said reject means being adapted to displace the bar supporting means into the bar discharge position, and to effect relative movement of the jaws into their open position to discharge the rejected bar without immersion with the quenching bath, and means responsive to the operation of said reject means for diverting said rejected bar to a discharge position other than the position to which the quenched bars are discharged.
  • Apparatus according to claim 1 characterised in that the advancement of each bar through the apparatus including the quenching bath, is etfected by a series of fluid pressure operated rams, the control valves of which are actuated by solenoids, the energising coils of which form part of an electric circuit embodying a controlling pyrometer responsive to bar temperature, immediately prior to quenching, and to an electrically operated timing device controlling the duration of bar immersion within the quenching bath.
  • the bar supporting means as a whole is movable under the control of said temperature responsive controlling device and timing device between two raised positions, namely a bar receiving position, in which the opening presented by the two sets of jaws is in the one case, namely the bar receiving position, directed towards the bank, and in the other case, namely the bar discharge position, directed towards a bar collecting trough or other collecting element to which the bars are discharged'in a direction away from the bank, the bar supporting means being also adapted with the jaws in the closed position to be displaced into and out of a lower quenching position by the respective operation of the temperature responsive controlling device and the timing device, said bar supporting means being mounted upon a rotatable shaft, the rotation of which serves to displace the bar supporting means between each of its several positions, the shaft being connected to a rack wheel which engages with a toothed rack connected to one of two piston rods of a double ram cylinder, the rod of the other piston of which is fixed to the base of the apparatus
  • timing device comprises an electric motor connected through an electrically controlled clutch to a wiper form of timing contact, with means to engage the clutch concurrently with the displacement of the bar supporting means in a direction to immerse the bar within the quenching bath.

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Description

Nov. 4, 1969 A. TRAVIS ETAL APPARATUS FOR USE IN EFFECTING CONTROLLED QUENOHING 0F METAL IN BAR FORM 9 Sheets-Sheet 1 Filed Jan. 27. 1967 INVQMTORS.
ALFRGD TfiAvls QHILV Q20 FT 7 Nov. 4, 1969 A. TRAVIS ETAL 3,476,371
APPARATUS FOR USE IN EFFEGTING CONTROLLED QUENGHING OF METAL IN BAR FORM Filed Jan. 27, 1967 9 Sheets-Sheet 2 (NVNTOEQ.
Alf-KGB TRAVIS @MLJP CRO N am? KW Nov. 4, 1969 A. TRAVIS ETAL APPARATUS FOR USE IN EFFECTING CONTROLLED QUENCHING 0F METAL IN BAR FORM Filed Jan. 27, 1967 9 Sheets-Sheet 5 9 Sheets- Shut 4 i969 A. TRAVIS ETAL APPARATUS FQR USE IN EFFECTING CONTROLLED QUENCHING OF METAL IN BAR FORM Filed Jan. 27, 1967 v i vmues, ALFRQ) TRIM/45 Q311 CROFT 6* K v ABM Nov. 4, 1969 A. TRAVIS ETAL APPARATUS FOR USE IN EFFECTING CONTROLLED 3,476,371 QUENCHING OF METAL IN BAR FORM 9 Sheets-Sheet 5 Filed Jan. 27, 1967 INVIU'TOQSI Nov. 4, 1969 TRAVIS T L 3,476,371
APPARATUS FOR USE IN EFFECTING CONTROLLED QUENCHING 0F METAL IN BAR FORM Filed Jan. 27, 1967 9 Sheets-Sheet 6 IMVMT QS. ALHQen TRQ-l/IS 1 mm? C FT,
3,476,371 QUENCHING OF Nov. 4, 1969 A. TRAVIS ETAL APPARATUS FOR USE IN EFFECTING CONTROLLED METAL IN BAR FORM- 9 Sheets-Sheet 7 Filed Jan. 27, 1967 1 i a mm mm fiflhfi i, mm on Dw "EH5 2 a E a Ha l x mm hm m i I E E I DHmH-BHU l E a HOME 3 E a mum-r0 es. ALFEGD TR @euuP CRO GT W AGMYK 9 Sheets-Sheet 9 Nov. 4, 1969 A. TRAVIS ETAL APPARATUS FOR USE IN EFFECTING CONTROLLED QUENCHING OF METAL IN BAR FORM Filed Jan. 27, 1967 mm E wmsoLro 6mm m E G T p HS o v c United States Patent 3,476,371 APPARATUS FOR USE IN EFFE'CTING CON- TROLLED QUENCHING 0F METAL IN BAR FORM Alfred Travis and Philip Croft, Stockport, England, assignors to Executors of James Mills Limited, Stockport, England, a British company Filed Jan. 27, 1967, Ser. No. 612,178 Int. Cl. C21d 1/62 US. Cl. 2666 11 Claims ABSTRACT OF THE DISCLOSURE This invention relates to apparatus for effecting in an automatic manner the controlled quenching of steel and other metal in bar form.
BACKGROUND OF THE INVENTION Field of the invention This invention relates to a new or improved apparatus for use in effecting the controlled quenching of metal in bar form. Although the invention has been developed specifically in connection with the method of quench hardening certain classes of steel, in accordance with the invention the subject of our prior Patent No. 3,111,- 436, the apparatus the subject of the present invention is considered to be of general application to the controlled quenching of any steel, as well as of other metals in bar form, using quenching baths of water, or of oil or other media in place of water.
Description of the prior art In controlled quenching, for example in accordance with the invention the subject of our prior Patent aforementioned, it is necessary that the bar should be quenched from a specific elevated temperature or temperature range, and it is also necessary that the bar should be in the quenching medium for a predetermined period of time dependent on the composition of the steel or other metal, the cross-sectional dimensions of the bar, the quenching medium and the properties desired in the steel or other metal after quenching.
The present invention has for its object the provision of a new or improved apparatus for effecting in an automatic manner the controlled quenching of steel and other metal in bar form, and which takes into consideration the foregoing requirements.
SUMMARY OF THE INVENTION According to the present invention, we provide an apparatus for effecting the controlled quenching of steel or other hot metal bars comprising:
(a) A bar receiving bank,
(b) Means for advancing a succession of hot bars to the bank,
(c) A quenching bath adapted to contain the required quenching medium,
((1) Bar supporting means movable between three different positions, namely a bar receiving position, a bar immersion position in which the bar is immersed within the quenching bath, and a bar discharge position, in which the bar is discharged from said supporting means,
(e) Means for feeding the bars from the bank to the bar supporting means when the latter is in the bar receiving position, and so that the bars are fed successively thereto in the same order as that in which they are advanced in the heated state to the bank,
(f) Control means responsive to the temperature of each bar, arranged to initiate the movement of the bar supporting means after a bar has been fed thereto and into the bar immersion position to immerse the bar within the quenching bath when the temperature of the hot bar has fallen to a value corresponding to the required bar quenching temperature or range of temperature,
(g) Bar reject means operated by said control means adapted to effect discharge from the apparatus without quenching of any bars fed or about to be fed to the supporting means at a temperature below the temperature or below the minimum value of the temperature range required for the bar just before quenching,
(h) A timing device arranged to control the duration of immersion within the bath of the bars by the supporting means, and
(i) Said bar supporting means being arranged to effect discharge of the quenched bars therefrom after their immersion in the quenching bath for the required period of time.
The bar reject means operated by said temperature responsive control means may be arranged to discharge bars at a temperature below the designed temperature without the bars so discharged being supported at all by the bar supporting means, but preferably each bar would be fed to the supporting means and the control means would be arranged so as to be responsive to the bar temperature when the bar is on the supporting means.
Preferably the bar receiving bank comprises a series of bar locations such as pockets spaced apart from one another in a direction transverse to the direction of bar feed to the bank, and the means for feeding the advancing bars to the bank comprises a bar transfer device responsive to the presence of a bar in the rearrnost of the succession of bar occupied bank locations, so as to deposit the next successively advancing bar in the location next in rear (in the direction of bar advancement) to the location already occupied by the bar last fed thereto.
Herein the expressions front and rear have reference to the general direction of bar advancement through the apparatus.
Preferably the bar supporting means comprises two sets of bar retaining jaws relatively movable under the control of both the temperature responsive control means as well as under the overriding control of the timing device between a closed bar retaining position and an open bar receiving and discharge position, and the bar supporting means as a whole may be movable under the control of said control means between two raised positions in each of which the jaws are in an open position, namely a bar receiving position, in which the opening presented by the two sets of jaws is directed toward the bank, and a bar discharge position in which the jaw opening is directed towards a bar collecting trough or other collecting device to which the bars are discharged in a direction away from the bank, the bar supporting means being also adapted with the jaws in the closed position to be displaced into and out of a lower quenching position by the respective operation of the temperature responsive control means and the timing device.
The bar transfer device aforementioned may comprise a bar feeding element embodying a bar supporting part and a bar engaging part, which two parts are spaced relatively apart in a direction transverse to the direction of bar feed to the bank, by a distance corresponding to the transverse spacing between adjacent bar locations, the bar engaging part of the feeding element being adapted to engage and thus to sense a bar in an already occupied location and there being means for displacing the bar feeding element in an orbital path to deposit the fed bar into an unoccupied location immediately in rear of the bar occupied location sensed by said bar engaging part, said bar feeding element being driven in its orbital path through a slippable clutch adapted to permit of the orbital movement of the bar feeding element, varying in accordance with the extent of occupation of the bank, as determined by the sensing action of the bar engaging part of the bar feeding element.
Preferably, the means for feeding the bars successively from the bank to the bar supporting means comprises a walking beam element, the operation of which is actuated by a device responsive to the presence or absence of a bar on the bar supporting means after the latter has returned to its bar receiving position, the arrangement being such that the walking beam operates to feed a bar to the supporting means when empty, each time this is in its bar receiving position and simultaneously feeds by one step, i.e. one location in a forward direction any bars which have accumulated on the bank successively behind the foremost location previously containing the bar in course of being fed by the walking beam to the supporting means. I
Preferably the apparatus includes bent bar actuated means responsive to failure of the jaws of the supporting means to move relatively into their closed position, as a result of more than a permissible departure of the bar from straight configuration, said bent bar actuated means being adapted to displace the bar supporting means into the bar discharge position, and to effect relative movement of the jaws into their open position to discharge the so rejected bar without immersion within the quenching bath, and there being means responsive to the operation of said bent bar actuated means for diverting said discharged bent bar to a discharge position other than the position to which the quenched bars are discharged.
BRIEF DESCRIPTION OF THE DRAWINGS One preferred form of apparatus will now be described with reference to the accompanying drawings in which:
FIGURE 1 is a plan view of one form of apparatus embodying the present invention.
FIGURES 2 and 2A are plan views to an enlarged scale of certain portions of the apparatus as depicted in FIGURE 1.
FIGURE 3 is a front elevation of part of the apparatus as depicted in FIGURE 2.
FIGURE 4 is a crosssectional view of the apparatus looking in a direction from right to left in FIGURE 1.
FIGURE 5 is a cross-sectional view to an enlarged scale of part of the apparatus depicted in FIGURE 4.
FIGURES 6, 7, and 7A are respectively diagrams of the pneumatic circuit and the electric circuit constituting the control means of the apparatus depicted in FIG- URES 1 to 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring firstly to FIGURES 1 to 5 of the drawings, the mechanical construction of the apparatus and the manner in which the various parts coact mechanically with one another will firstly be described, before explaining completely the sequence of operations and the manner in which these are controlled by the pneumatic and electric circuits respectively depicted in FIGURES 6, 7 and 7A.
The apparatus illustrated in the drawing comprises a bar receiving bank 10 and means generally indicated at 11 for feeding to the bank 10 a succession of hot rolled bars directed from the bar or rod mill, which may be of conventional form and is not illustrated.
The bars are advanced from the mill over a bar supporting table 12 adjacent to which is a hot bed 13 of conventional form with a gate 14 at the forward end of the table 12. The gate 14 is normally in an open position, but under the control of pneumatic ram P1 is displaced into a closed position by the advance of a bar completely past the gate, so as to prevent more than a single bar at a time being fed past the gate. With the gate 14 closed and the apparatus completely filled with last ba s a t ng s be q str tli th st l m y W i to operate, with the bars emerging therefrom being then diverted from the table 12 onto the hot bed 13 by conventional pusher means not shown. Otherwise the hot bed 13 is not used, and would not be required at all, assuming that the rate of quenching of the bars can be invariably geared to the output from the mill, so that the bank 10 can never be filled beyond capacity.
The means 11 for feeding the hot bars to the bank 10 comprise a series of power driven bar feeding rollers 15 which are arranged to engage only with the underside of the bar, so as to advance this in the direction of the arrow 16 to the end stop 17 aligned with the row of feed rollers 15. The arrangement is such that the bars are advanced successively by the rollers to a position adjacent one side, namely the rear side 10:: see FIG. 4 of the bank 10, and the latter is of elongated configuration, so as to have a length corresponding to the length of the longest bar designed to be fed to the apparatus from the mill.
The means 11 for feeding the bars successively to the bank 10 further comprise a bar transfer device consisting of a plurality of bar feeding elements 18, each comprising a bar supporting part 19, together with a bar engaging part 20 (see FIGURE 4).
Each of these bar feeding elements 18 may, as shown in FIGURE 4, be formed of rod to provide a bar supporting part 19 in the form of a V notch adjacent to which, but on the forward side in the direction of bar feed, the bar engaging part 20 is provided.
A number of these bar feeding elements 18 are provided spaced apart along the length of the bank 10, and are carried upon a supporting tube 21 which may be fixed or preferably rotatably mounted in bearing blocks 22 in turn carried on the free end portion of one of a series of levers 23, the opposite end of each lever being pivoted to the upper end of fulcrum link 24, the lower end of which is hinged to the base 25 of the apparatus. The lever 23 intermediate its two ends is pivoted at 26 to piston rod 27 connected to the piston of pneumatic lifting ram P2, which serves to lift the bar feeding elements 18 prior to their movement in a lefthand direction in FIG. 4, to transfer the bar towards the quenching bath. This ram P2 is pivoted at 28 to the middle part of substantially vertical control link 29, the upper end of which is pivoted to one end of intermediate link 30, the other end of which is pivoted at pivot 26 to lever 23.
The lower end of control link 29 is mounted on rock shaft 31, which is driven through a slippable clutch 32 from bar feeding element pneumatic ram P3, fulcrumed at 33 to base 25. This ram P3 serves to transfer in a substantially horizontal direction, i.e. from right to left in FIGURE 4, the bars in a direction towards the quenching bath and the provision of the slippable clutch 32, permits of the amplitude of bar feeding movement of the bar feeding element 18, which movement is in a direction transverse to the length of the bank 10, varying in the manner later described in accordance with the extent of occupation of the bank 10 by bars previously fed thereto, with the piston of ram P3 each time completing its full stroke.
Thus the movement of the bar feeding element 18 is controlled by the lifting ram P2 and the transfer ram P3, respectively operating to displace the bar feeding element in a substantially vertical and a substantially horizontal direction, so that the bar feeding element 18 in the course of its feeding and return stroke performs an orbital movement.
The bar receiving bank 10 is formed by a large number of bank plates 34 arranged in parallel relationship but spaced apart in a direction along the length of the bank 10, and the upper edge of each of these plates 34 is of saw tooth configuration, so as to provide a series of upwardly directed substantially V-shaped pockets 3S spaced apart from one another in a direction perpendicularly transverse o the length f e ba with a h or the pockets 35 of one bank plate 34 aligned in a direction of bank length, with one of the notches of each of the other plates 34. Thus the bank comprises a series of pocket like bar locations constituted by the notches 35 and spaced apart from one another in a direction transverse to the direction of arrow 16 of bar feed to the bank. The arrangement permits of the accumulation on the bank of a variable number of bars 36 within the overall capacity of the bank, so that it is not required precisely to co-ordinate the rate of discharge of the bars from the mill with the feeding of the bars into the quenching bath, the provision of the bank 10 providing for the necessary flexibility in operation of the apparatus without it being normally necessary to make use of the hot bed 13.
At the side 10b of the bank 10, i.e. the discharge side, and which is opposite to the rear or input side 10a of the bank, is arranged a quenching bath 37 in the form of a trough which extends for the full length of the bank, but below the level thereof, and it is adapted to contain the required quenching medium which in the preferred application of the invention relating to the aforementioned prior patent, is water. This bath 37 may be provided with water supply means and a discharge weir, not shown, with provision for a constant flow of water into and out of the quenching bath, so as to maintain this at a predetermined temperature or temperature range, despite the heat supplied thereto from the bars during quenching.
Above the quenching bath 37 between this and the dis charge side 10b of the bank 10, is bar supporting means 38 for advancing the bar from the bank into the quenching bath, and for supporting the bar therein, as well as for discharging the bar from the bath after quenching.
This bar supporting means comprises two sets of bar retaining jaws 39, 40, which are relatively movable between an open bar receiving discharge position in which the relative disposition of the two sets of jaws is shown in full outline in FIGURE 5, and a closed bar retaining position corresponding to the position of the parts when immersed within the water 41 in the bath 37.
The jaws 39 are each of notch like configuration, and the jaws 40 are constituted by a series of arms.
The jaws 39 are carried upon a main jaw shaft 42, supported for rotational movement on fixed fulcrums 43 carried on part of the base 25, and the jaw arms 40 are carried on a jaw spindle 44 which extends parallel to the shaft 42, and which is rotatably supported from the jaws 39. As shown in FIGURES 2 and 3, the spindle 44 at the end thereof which is nearest to the table 12 has mounted thereon a follower roller 45, which engages with wedge member 46, which is mounted on the adjacent end of shaft 42, and along the length of which it is free to slide.
For this purpose the wedge member 46 is pivoted at 46a to an upstanding part of bracket 47 connected to collet 48 which is also axially slidable along the length of shaft 42.
The periphery of collet 48 is grooved at 4811 to receive the abutment pins 48b carried on yoke 48c mounted on vertical pivot 48d, and connected through link 48e to the I piston rod of pneumatically operated jaw opening and closing ram P7.
The arrangement is such that when the piston rod of ram P7 is displaced, the collet 48 and bracket 47 and wedge member 46 connected to the bracket, are all slidden in a direction along the length of shaft 42 relative to shaft 44, so as by the engagement of wedge member 46 with'follower roller 45 to effect oscillatory movement of spindle 44 relative to jaw shaft 42, and thus to displace the movable jaw arms 40 relative to the jaws 39, between their open and closed positions.
The wedge member 46 is adjustable about its pivot 46a relative to bracket 47, so as to vary the inclination of its wedge face 46b to the adjacent axis of spindle 44, and thus to vary for a given axial displacement of wedge 46 by ram P7 of the rotational movement of spindle 44 and associated jaw arms 40, in accordance with the diameter of the bar to be quenched, the greater rotational movement of the jaw arms 40 from the open to the closed position being necessary in the case of the small diameter bars than with large diameter bars to effectively retain the small diameter bars within the jaws, it being understood that in the case of larger diameter bars there is a limit to the closing movement of the jaw arms 40 by reason of them engaging with the bars within the jaw notches 39.
To effect the foregoing adjustment of wedge member 46, bracket 47 carries adjusting screw 47a, the free end of which engages with adjacent face of wedge member 46, so as to swing this about pivot 46a, while the wedge member is further provided with locking screw 46c carried on an adjacent part of bracket 47, which extends through an arcuate slot in the wedge member.
The bar supporting means 38 is movable between an upper bar receiving position 38a in FIGURE 5, in which it is disposed adjacent the discharge side 10b of bank 10, so as to be adapted to receive a bar therefrom, and a lower quenching position 38b in which the two sets of jaws are immersed Within the water or other quenching medium. The said movement in each direction is through an intermediate position 38c, which prior to quenching constitutes a holding position at which the temperature of the bar is being determined prior to quenching, and which postion 380 after quenching is the bar discharge position. 9
As will be seen from FIGURE 5, the aforementioned movement of bar supporting means 38 requires that spindle 44 should swing bodily about the axis of main jaw shaft 42, and this is permitted by the above described parts 46, 47, and 48 being all turnable with follower roller 45 about the axis of shaft 42, such turning movement being permitted by the fact that the abutments 4817 on yoke 48c engage freely within the collet groove 48a.
Means are provided for feeding the bars 36 from the bank 10 to the bar supporting means 38 when this is in the bar receiving position 38a, in such a manner that the bars are fed successively thereto in the same order as that in which they are advanced in the heated state to the bank. Such bar feeding means, see FIGURE 5, comprises a walking beam device 49 constituted by a ,series of bar feeding strips 50, there being a strip disposed in the space between each pair of bank plates 34, each strip 50 being of saw tooth configuration at its upper edge, so that each strip 50 is formed with a series of bar feed edges 51 which slope downwardly and forwardly in the direction of bar feed, each of these bar feed edges 51 having a pitch or relative spacing which is the same as that of the bar location pockets 35 of each plate 34.
Each of the strips 50 is carried on a dependent walking beam arm 52 supported from base 25 by fulcrum link 53, and the lower part of each arm 52 is connected by walking beam drive arm 54 to walking beam driving mechanism 55 of conventional form, and operated by a pair of walking beam pneumatic rams P4, the operation of which, as later described herein, is controlled by the particular disposition of the bar supporting means 38 in its bar receiving position 38a with the two sets of jaws open.
Fulcrum link 53 extends substantially parallel to drive arm'54, and the arrangement is accordingly such that the walking beam arm 52 with its associated strips 50 is constrained to move in a substantially vertical direction between its lower inoperative position depicted at 49a in FIG. 5, and its upper bar feeding position depicted at 49b in that figure.
As shown in FIG. 5, each bar feed edge 51 of each strip 50 is disposed in vertical alignment with bar receiving corner 35a of each notch or pocket 35, with each bar feed edge 51 also extending beneath that crest 56 of each bank plate 54, which is on the forward side of the aforesaid corner 35a. The arrangement is accordingly such that when each of the strips 50 are raised by the operation of rams P4 from their lower inoperative position 49a to their upper bar feeding position 49b, in which they extend above the level of bank plates 34, each bar within each of the notches or pockets 35 will be raised by engagement with the adjacent bar feed edge 51 on strips 50, clear of that crest 56 which is on the immediate forward side of the bar concerned, so that the latter rolls gravitationally downwardly and forwardly of the so engaged bar feed edge 51 past the aforementioned adjacent notch into the forwardly adjacent corner 50a of the associated notch 50b of strip 50; i.e. bar originally at the position 36a in FIG. will, with the feeding strips 50 in the raised position, now be in the position 36b so that when the feeding strips 50 are again lowered by rams P4, the so forwardly advanced bar will now engage with the side of that pocket 35, immediately in advance of the pocket just previously occupied by the bar, so as to roll downwardly into the corner 35a, i.e. bar originally at position 36a will now be at position 36 in FIG. 5. Thus each time the walking beam 49 is raised and lowered, each of the bars 36 within the pockets 35 are simultaneously advanced in a direction towards the discharge side 10b of the bank, i.e. from right to left in FIGURE 4, by a distance corresponding to the pitch distance of the bar locations 35.
As later further explained, before the foregoing elevational movement of the walking beam strips 50 can commence, the bar supporting means 38 must be in the upper bar receiving position 38a; there must be a bar in the foremost of the locations 35, namely, in location 3511 which is nearest to the discharge side 1015 of the bank; also the transfer device must be in its retracted position or on its return stroke towards such position. Assuming that the foregoing conditions are fulfilled, a bar previously within the foremost location 35b will slide down the foremost of the walking beam edges 51 as well as sliding down the adjacent downwardly sloping discharge nose 57 of the bank plates 34, so as to be received within the open jaws of the supporting means 38 in its bar receiving position 38a.
The jaws 40 will now move into the closed position with the walking beam strips 50 still in their raised position in which they will remain until as later described, the bar supporting means 38 commences to travel towards the intermediate position 38d (see FIGURE 5). The walking beam strips 50 will now move downwardly so as to deposit the next successively advancing bar into pocket or location 35b, after which the walking beam strips will return to their initial position ready to again deposit the next successively advancing bar into pocket 35b.
It will be understood from the foregoing description that the walking beam device 49 advances the several bars 36 in a direction towards the bar supporting means 38, in such a manner that the bars are fed successively to the bar supporting means 38 in the same order as that in which they are advanced in the heated state to the bank. It is thereby possible by suitable control of the rolling mill temperature for the bars to be advanced by the bar feeding means 11 and bar feeding elements 18 to the bank 10 at a temperature such that by the time each bar has reached the foremost bank location 3512 and the bar supporting means 38 is in its bar receiving position, the bar will have cooled to a temperature corresponding to the required temperature at which the bar is to enter the quenching bath. At the same time the step-wise advancement of the bars across the bank 10 provide for a slow cooling, i.e. air cooling, of the bars prior to quenching, which is an essential feature of the invention the subject of the prior patent.
The bar supporting means 38 are displaced from the bar receiving position 380: to the intermediate or centre position 380 by means of pneumatic ram P5, and are displaced from the intemediate or centre position 38c to the immersion position 38b within quenching bath 37, by a further pneumatic ra n P8, constituting a quenching ram,
As shown in FIG. 4, these two ams P5 and P8 are arranged in tandem, so as to constitute a double cylinder 58 formed as one member, and having two pistons, the piston rods 59, 59a of which relate respectively to rams P5 and P8. Piston rod 59, see FIG. 4, is fixed to the base 25, with the cylinder 58 being vertically movable and piston rod 59a is connected to vertically extending rack 60, which meshes with rack pinion 61 mounted on main jaw shaft 42. The arrangement is such that when the air pressure is supplied merely to ram PS, the cylinder 58 and piston rod 59a are displaced vertically without relative movement therebetween by an amount such as to rotate shaft 42 by a distance sufiicient to displace the bar supporting means 38 from its bar receiving position 38a to its intermediate position 38c, while when the air pressure is supplied to ram P8 the associated piston rod 59a is displaced relative to cylinder 58 in the same direction by a further distance to effect further rotation of shaft 42, and thus displace the bar supporting means 38 from its intermediate position 380 to its quenching position 38b.
The bath 37 at the side thereof furthest from the apparatus is provided with a bar discharging table 62, adapted to receive bars discharged thereon from the bar supporting means 38, when in the intermediate position 38c, to which the bar is raised after quenching, before the jaws 39 open to discharge the quenched bar therefrom. This table 62 slopes downwardly away from bath 37 to a quenched bar receiving trough 63, in which the quenched bars accumulate, from which they are removed periodically as convenient, and in which trough 63 the bars may be allowed to remain so as to affect final slow air cooling in which evening up occurs of the temperature difference between the surface layers and the core of each bar following the interuption of the water quenching, which is a further essential feature of the method of quench hardening the subject of the prior patent.
The bar reject means, arranged to effect discharge without quenching of any bars at a temperature below the requisite temperature prior to quenching, comprise the provision of a series of deflector arms 64 supported at one end on bar deflector shaft 65, with the arms 64 spaced at intervals therealong, the shaft 65 being pivotable under the control of a pair of bar reject pneumatic rams P6, between an upstanding position as shown in full outline in FIGURE 4, and a horizontal reject position depicted in dashed outline in FIGURE 4, in which the deflector arms 64 lie across the mouth of quenched bar receiving trough 63, so as positively to prevent the discharge of unquenched bars thereto, and instead to deflect such unquenched bars into reject bar receiving trough 66, disposed, as shown in FIGURE 4, beyond the outer side of trough 63. Such reject means also serve to deflect into trough 66 any non-straight bars, in manner later explained, so that trough 66 receives all bars which are rejected either by reason of being of insufficiently straight configuration, or being at a temperature too low before quenching. With the arms 64 in their upstanding position, as shown in FIGURE 4, they effectively prevent any bars intentionally discharged to trough 63 inadvertently passing beyond the same into reject trough 66.
Reference is now made to FIGURE 6 of the drawing, in which is depicted the pneumatic circuit for operating the various pneumatic rams, P1 to P8 inclusive, the function of which has already been described. Each of these rams is a double acting ram, and each ram P1 to P8 is respectively controlled by solenoid operated air valve V1 to V8, each valve being connected to opposite ends of the associated ram by a pair of air lines AL, with each an valve being provided with the usual supply line SL, connected to air storage tank AST having main air suppl line MSL. Each air valve is further provided with exhaust air line EL.
In FIGURE 6, each of the several rams P1 to P8 is depicted with its associated iston rod PR, in the position occupied when the solenoid controlling each of the air valves V1 to V8 inclusive is energised. Thus when the solenoids controlling rams P4, and P8 are energised, the piston rods thereof are retracted, while in the case of the remaining rams, when their respective solenoids are energised, the piston rods are advanced as shown on the drawing.
In the case of rams P4 and P6, in respect of each of which a pair are provided, for simplicity in drawing, only one of the two rams in each pair'is illustrated in FIG. 6, and for simplicity in description, will be so referred to, i.e. in the singular in the description of FIGURE 7 and 7A. It will be understood that the two rams in each pair have a common air valve, i.e. V4 in the case of the two rams P4, and V6 in the case of the two rams P6, and operation of each ram in the respective pairs being identical.
The solenoid for operating each of the air valves V1 to V8 inclusive, is respectively' controlled by contactor coil S1 to S8 inclusive, and which are embodied in the electric circuit depicted in FIGURES 7 and 7A, forming with the pneumatic circuit for operating the rams the control means for the apparatus, depicted in FIGURES 1 to 5.
Referring now to FIGURES 7 and 7A, the various switches and contacts are depicted in the position which they occupy when the circuit is ide-energised, and in accordance with convention the symbols which are shown within circles, namely those bearing the capital letter sufiix C, R and S, all denote contactor coils. The relay contacts of these coils bear the same drawing reference in respect of two of the digits in each reference as the drawing reference of the associated contactor coils themselves, the letter reference in this' "case being a small letter reference; e.g. each relay contact r1 is controlled by the one contactor coil R1. As will be seen from FIGS. 7 and 7A, some of the contactor coils "have more than one set of relay contacts. In respect of each relay contact when their corresponding coils are energised, such contacts, if depicted closed, will open, and if depicted open in FIGS. 7 and 7A, will then close.
Insofar as the electric circuitis conventional per se, it will in general be sufiicient to describe it simultaneously with the description of the sequence of operation of the apparatus under the overriding control of the electric circuit.
However, it must first be stated that the circuit embodies a pyrometer 67, which is a known form of optical pyrometer, mounted, as shown in FIGURE 1, at a position so as to be sensitive to' the temperature of the bar about to be quenched, when this is in the mid position 38c. The pyrometer is provided with three control switch contacts Tr, Ta'l and Ta1(i), the opening and closing of which is in the known manner forming no part of this invention, under the control of the temperature sensitive element of the pyrometer, itself responsive to the temperature of the bar when in the mid position 38c.
The circuit further includes a timer motor 68 of known form, which is in circuit with solenoid contactor coil S8 controlling ram P8, and which can be driven for an adjustable period of time thruogh electrically rotated timer clutch 69. The arrangement is such that after the timer motor has operated for the predetermined period, the contactor coil S8 is de-energised to de-energise the associated solenoid controlling air valve V8, associated with pneumatic ram P8, so as then to effect retraction of the now quenched bar from the quenching bath 37.
The circuit is energised from the main supply leads 70, and the connection of these to the various switches and contactor coils will be apparent from the drawing.
The sequence of operations will now be described with particular reference to FIGURE 7. Initially, all of the contactor coils for operating the various switches on FIG. 6 are de-energised, so that the piston rod of ram P1 will be in its retracted position corresponding to the de-energisation of its associated solenoid, in which position gate 14 is open to permit of the feedng of the first of a succession of bars to the bank 10 from the bar supporting table 12.
The sequence of operations is commenced by closing start switch 71 provided on an operating panel 72 (see FIG. 1). The effect of closing start switch 71 is to energise contactor coils R3 and R30, to close the illustrated open relay contacts r3 and r3a, so as to effect a preliminary energisation of certain parts of the circuit.
Concurrently, the bar is advanced along the bank 10 by the feeding means 11, power driven continuously independently of the control of the electric circuit, so that the bar is advanced to end stop 17, adjacent to the lower side of which is disposed flag switch lsl, having a detent engaged by the end of the bar as it reaches stop 17, so as to close this flag switch and energise contactor coil R1, to close the associated switch contacts r1. The effect of this is to energise the contactor coils S1 and S2, closing their associated contacts s1 and s2, which are respectively associated with pneumatic rams P1 and P2.
Thus, the piston rods of these two rams are advanced, so as in the case of ram P1 to displace gate 14 into its operative position, to prevent the advance of a second bar, until the preceding bar has been lifted clear of the feeding means 11.
The above actuation of ram P2 raises bar feeding elements 18 into engagement with the underside of the adjacent bar, to lift this clear of the feeding means 11, into the position depicted in FIG. 4. As the feeding elements 18 reach their fully lifted position they engage with a detent of transfer start switch [s3 diagrammatically depicted in FIG. 4, so as to close this switch from its previously open position. This switch is in series with contacts r3a, previously closed by contactor coil R3a in series with normally closed switch ls3b and with walking beam control switch ls2, the detent of which is engaged to close this switch when the walking beam 49 is in its lower or inoperative position, as is at present the case, as the solenoid controlling walking beam ram P4 has not yet been energised.
Thus, as soon as switch [s3 is closed by the lifting of the bar feeding elements into the FIG. 4 position contactor coil S3 is energised. Its contact s3 when closed at once actuates the solenoid controlling transfer ram P3, which now displaces the feeding means 18 in a direction to transfer the bars to the vacant pocket 35 of bank 10, which is closest to the quenching bath 37.
By reason of the slippable clutch 32, the piston rod of ram P3 completes its stroke irrespective of this transfer movement of the bar feeding means 18, and in association with rarn P3 is normally closed spring loaded bar lowering switch ls2a, having a detent engaged by the piston rod of transfer ram P3, so as to open the switch ls2a when the ram has completed its movement corresponding to the permissible limit of bar feeding means 18 above the notches of bank 10. The switch ls2a is in series with the solenoid contacts 52, and since contacts r1 have previously opened by d e-energisation of coil R1 contactor coil S2 is now de-energised, so that each of its associated contacts s2 open to retract the piston rod or ram P2, and lower the feeding means 18 to deposit the bar within the aforementioned vacant notch 35 nearest bar 37 and at the same time to thus open switch [s3 responsive to the vertical position of feeding means 18.
In association with the piston rod of ram P2, is a spring loaded normally closed switch ls3a, the detent of which is engaged to open switch ls3a only when the piston rod of ram P2 is retracted, i.e. to a position corresponding to the lowered position of feeding means 18. As switch ls3 has already opened, the effect of opening switch ls3a is to de-energise contactor coil S3 controlling transfer ram P3, the piston rod of which is retracted to displace the feeding means 18 already in a lowered position, in a righthand direction in FIG. 4, leaving the bar deposited in the above mentioned vacant pocket 35.
As the feeding means completes its return movement to its initial inoperative position below feeding rollers 15, i.e. below its full line position in FIG. 4, it opens the normally closed swtch lsla diagramatically shown in FIG. 4, to de-energise contactor coil S1 and thus advance the piston of its associated ram P1 to open gate14, to permit of the advancement of a second bar, with the feeding means 18 ready to engage with it.
The de-energisation of contactor coil S3 by the above mentioned opening of switch ls3a, causes contacts s3a controlled by coil S3 to return to their illustrated closed de-energised position.
Contact s3a is in series with switch ls4a, which is closed so long as the bar jaws 39, 40 are in their top position 38a. Also in series with the switch s3a is switch ls4b, which is closed by the presence of a bar in the foremost pocket 35a.
In the operation as so far described, there must either already have been a bar in pocket 35a or else if this pocket was previously vacant, the above described transfer operation of the bar feeding means 18 would have deposited a bar in this pocket, so as to engage with the detent on switch ls4b associated with this pocket, and to close the switch against associated spring loading.
Thus, so long as a bar occupies the foremost pocket 35a, the above mentioned closure of contact s3a by deenergisation of contactor coil S3, will energise contactor coil S4 controlling walking beam ram P4, the piston of which ram is now retracted. Such retraction causes the walking beam 49 to be raised and then lowered in a substantially vertical direction, so as in the manner earlier described to advance each bar towards the quenching bath by a distance corresponding to the pitch of the pockets 35, so that the bar in the foremost pocket 35a is now deposited on discharge nose 57 down which it falls to be received by the at present open jaws 39, 40, in their fully raised position depicted in full outline at 380 in FIG. 5.
In association with the walking beam 49 is a spring loaded normally open detent operated switch ls9 in circuit with contactor coil R4, which is closed by the above mentioned movement of walking beam 49 into its raised position, so as to energise coil R4 of relay contact R4, which is in series with contactor coil S7 controlling jaw opening and closing ram P7, and is also in series with normally open timer switch s4a closed by the energisation of contactor coil S4, but incorporating an adjustable time delay device of known form. The object of this is to allow time for the foremost bar discharged to the jaws 39, 40 by the walking beam, to reach these jaws before coil S7 is energised to displace ram P7 in a direction to close the jaws 39, 49 after the reception of the bar therein. 7
Contactor coil S7 also controls a normally open switch s7a provided with a timing device, so as when energised to close s7a after a time interval long enough to allow for full closure of the jaws 39, 40, before by such closure of switch .s'7a to energise contactor coil 85 which through its relay contact s controls the solenoid operating ram P5, which lowers the closed jaws from the top position 38a to the mid or intermediate position 380.
Contactor coil S5 also controls timer start switch s5t, which is a double pole switch in circuit with step down transformer 73, the output of which is connected to the timer motor 68, so as to start the motor, but leaving the clutch 69 driven from the motor still disengaged.
Contactor coil S5 also operates pyrometer relay sSp, so as when energised to close the relay contacts and thus energise the relay coil CIT, to close the associated relay contact cit to supply current to pyrometer 67. This pyrometer, through a normally closed manually operable pyrometer selector switch PS8, is in circuit through normally closed relay s81 of contactor coil S8, with the contactor coil 86 which controls the solenoid actuating the bar reject ram P6. The arrangement is such that when the solenoid controlling this ram P6 is de-encrgised, the bar deflector arms 64 are in the upstanding or bar acceptance position permitting of controlled quenching.
As earlier mentioned, the pyrometer 67 incorporates two series of control switch contacts, arranged in parallel, namely switch contact Tr, which is in series with contactor coil S6 and arranged in parallel with the two in series switch contacts Tal and Ta1(i), which are themselves in series with the contactor coil S8, which coil controls the solenoid operating ram P8 for lowering the jaws 39, 40 from the mid position 38c to the quenching position 38b, and from this position back to the mid position 38c.
Pyrometer switch contact Tr isclosed when the bar temperature as measured by the pyrometer is below the minimum acceptable temperature for quenching, so as then to energise contactor coil S6, the contact Tr being open when the bar temperature is at or above the minimum acceptable temperature. Switch contact Ta1(i) is normally closed, but opens when the bar temperature as measured by the pyrometer is above the maximum acceptable temperature for quenching, the effect of opening this contact being to prevent contactor coil S8 being energised until the bar temperature has fallen to the maximum acceptable temperature. Pyrometer switch contact T01 is a normally open contact, which closes under the control of the pyrometer when the bar temperature approaches the minimum acceptable temperature for quenching, so as with Ta1(i) already closed then to effect energisation of contactor coil S8.
The pyrometer includes in the known manner, forming no part of this invention, provision for adjusting the temperature at which the three switch contacts Tr, Tal and Ta1(i) respectively open and close according to the metallurgical characteristics of the bar and the required heat treatment.
From the foregoing description of the construction of the pyrometer 67, it will be understood that with the bar now in the mid position 38c, in operative location to the pyrometer 67, if the temperature as measured by the pyrometer is below the minimum permissible temperature for quenching pyrometer switch Tr closes to energise contactor coil S6, thus displacing the piston rod of ram P6 into a position in which the deflector arms 64 lie across the mouth of the bar quenching trough 63.
In association with deflector arms 64 is normally closed spring loaded switch ls7, the detent of which is engaged by deflector arm 64 when in the horizontal bar rejecting position. The switch is in series with contactor coil S7 controlling the jaw opening and closing ram P7, and insofar as relay r4 has again opened, by reasons of the opening of switch ls9, consequent on the lowering of walking beam 49, the effect of opening switch 157 is to deenergise contactor coil S7, so that the piston rod of ram P7 retracts to open the jaws 39 and 40, and discharge the bar at the unduly low temperature into the reject trough 66.
If on the other hand, the temperature of the bar in its mid position 38c as measured by pyrometer 67 is at a temperature above the maximum temperature of the permissible quenching temperature range, switch Ta1( i) will open, closing when the bar temperature falls to maximum permissible quenching temperature, but with switch contact Tal as yet remaining open until the minimum value of this temperature range is approached, so as then to close and energise contactor coil S8 to thereby energise the solenoid which controls rarn P8, and thus to advance the still closed jaws and bar therewithin from the mid position 38c to the quenching position 38b, and immerse the bar within the quenching bath.
The energisation of coil S8 closes relay switch sSt which engages timer clutch 69, which energises a solenoid, not illustrated, and connected to timer clutch 69 to 13 engage the driven member of this clutch to the driving member, which driving member is connected through timer driving shaft indicated diagrammatically at 74 to the already driven timer motor previously energised by the earlier closure of double pole switch sSt.
The driven member of timer clutch 69 is connected through a driven shaft, which for convenience in the layout of the circuit diagram is diagrammatically indicated by the broken non-straight line 75, and the output end of this rotatable shaft 75 is connected to a rotary quench time contact Qtc, which is a normally closed switch in series with relay contacts r3a and relay s8 of contactor coil S8. As contactor coil R3a is energised, so long as start switch 71 is closed, the relay r3a is closed and relay s8 has already been closed by the previous energisation of coil S8 by the operation of the pyrometer 67, in closing its contact Tal. However, with the advancement of the heated bar to the quenching bath, the pyrometer is no longer subject to the temperature effect of the bar, so that its contact Tal will by now have opened. Accordingly, when the timer clutch 69 has completed its rotational movement, as determined by the timer motor 68, so as to open the normally closed rotary switch Qtc, contactor coil S8 will now be de-energised, thus de-energising the solenoid of the associated ram P8, to advance the piston rod of the latter and raise jaws 39, 40 with the bar therein to position 380, after quenching within the quenching bath for the required time interval, as determined by the operation of the timer motor. Such return movement of the bar supporting jaws from the bottom to the mid position, efiects closure of spring loaded normally open switch lsS, in series with contactor coil R2, which is now energised to open its normally closed relay contacts r2. These are in series with the still energised contactor coil S7, controlling jaw opening and closing ram P7, which contactor coil is now de-energised so as to effect retraction of the associated piston rod displacing the jaws 39, 40 into the open position, so as with the jaws at the mid position 38c to discharge the properly quenched bar into the bar receiving trough 63, which is designed to receive the properly quenched bars.
One of the relay contacts of coil S7, namely contact s7b is in series with contactor coil SSA, relay contact of which s5a is through the at present closed relay s5 in series with contactor coil S5, whose associated time delay switch s7a has now under the control of its timing device again opened, following de-energisation of associated coil S7. Thus the elfect of opening relay s5a is to de-energise coil S5 and its associated solenoid to advance the piston rod of the associated ram P5 and thus return the jaws 39, 40 to their upper position 38a, ready to receive a further bar.
As the jaws return to their upper position, they engage with a detent of the above mentioned spring loaded switch ls4a, to close this, and thus energise contactor coil S4 controlling walking beam ram P4, to advance a second bar from the foremost pocket 35a to the already open jaws 39, 40 thereupon initiating again the above described quenching cycle.
Switch ls4b will, of course, have already been closed by the feeding of a second bar to the foremost pocket 35a when the walking beam performed its cycle of operations preparatory to the quenching cycle just described, it being understood that concurrently with the removal of a bar from the foremost pocket 35a and its delivered to the open jaws in their top position 38a, a second bar will have been delivered to pocket 35a, so as to reclose switch ls4b. Should a bar not have been so delivered by this operation of the walking beam, in that all of the pockets 35 are now temporarily emptied, a further bar will now be delivered to the foremost pocket 35a by the already described operation of the bar feeding means 18, the electric circuit controlling the operation of which operates quite independently of the bar quenching cycle, so as continually to supply fresh hot bars to the several pockets during the quenching of each bar.
Accordingly, as soon as contactor coil S4 is re-energised by the return of the jaws to their top position 38a, to close switch ls4a, quenching of a further bar will be automatically initiated without any further operation by the operator being necessary. In other words, once the start switch 71 has been closed, to commence the above described complete cycle of operations, the controlled quenching of successive bars will continue so long as the hot bars are being supplied ot the apparatus from the bar mill or bank 13.
In series with contactor coils R3 and R3a is a normally closed stop switch 76, which when opened breaks the circuit to bring the cycle of operations to a standstill. In addition each of the solenoid controlling contactor coils S1 to S8 inclusive, is provided with normally open manually controlled press button switches mounted on switch panel 72, these switches being respectively designated msl to ms8 inclusive, and enabling any one of the corresponding solenoids and thus the corresponding rams P1 to P8 inclusive being manually controlled, egg. in testing particular sections of the apparatus.
Provision is made for rejecting without quenching any bars which may be delivered to the bank 10', and thus to the jaws 39, 40, in such a bent condition as to be unacceptable. For this purpose, in association with the movable jaw shaft 40 is a jaw full closed switch ls10, which is open when the jaws 39, 40 are fully closed, but otherwise is in the closed position, and in particular is closed when the jaws fail fully to close, despite closure movement of the jaw shaft 44, e.g. by reason of a bar to be quenched being bent by more than an acceptable amount.
Switch ls10 is in series with relays s5 and r4 of contactor coils S5 and R4 respectively, so that when each of these coils is energised prior to the discharge of a bar to the at present open jaws at the upper position 38a, coil R5 is energised. The latter is energised by the closure of switch ls9 when the walking beam completes its movement to deliver a bar to the at present open jaws in the upper position 38a after which coil S5 is energised as earlier explained, to close its above mentioned relay contact s5, and effect displacement of the jaws from the top to the mid position. In the event, however, of this jaw full closed switch ls10 remaining in the closed position, consequent on failure of the jaws to fully close, contactor coil R5 will now be energised, so as to open its relay r5p, which is in series with the above mentioned pyrometer switch Ta1, and to close its relay contact r5l in series with contactor coil S6. The effect of the foregoing is respectively to prevent the pyrometer when the bar is at the correct temperature, from energising coil S8 and to energise the contactor coil S6, so as, as earlier explained, to effect displacement of the bar deflector arms 64 into their horizontal bar rejecting position.
In order to avoid any possibility of the cycle of operations under the control of the pyrometer being undesirably repeated, the circuit includes two contactor coils CIT and CIR respectively referred to as instrument timerco'ils and instrument relay coils, which respectively control relay contacts cit(a:) and cit, and the two relay contacts cir. Relay contacts cit(a) embodies a time delay which permits of the contact closing after a predetermined time interval, and is in series with one of the two relay contacts air, and through this with the above mentioned switches of the pyrometer 67. Relay contact cit is in series with the other relay contacts air, and together are in parallel with relay contacts s6, s8 controlled by contactor coils S6 and S8, each of which last mentioned relay contacts are in parallel with one another, while being in circuit with instrument relay CIR.
The effect of closing these relay contacts s6, s8 in circuit with instrument relay coil CIR to energize this is to open relay air in series with the pyrometer contactor switches. Thus as soon as either coil S6 is energised to reject a bar or coil S8 is energised to advance a bar into the quenching bath, the current supply to the'pyrometer 67 is cut off, and the pyrometer remains de-energise-d until the circuit is ready to accept another bar for quenching. The re-energisation of the pyrometer is effected by the re-energisation of contactor coil S5, which as earlier described closes relay sp to re-energise instrument timer coil CIT and thus close the associated two relay contacts cit(a) and cit, and as the relay contact air in series with cit(a) has already been closed by the de-energisation of instrument relay coil CIR, following the de-energisation of coil 55, the circuit is now in a position to allow the pyrometer to repeat its above described temperature control operation. The reason for making relay contact cit(a) a time delay contact, is to allow time for the pyrometer to respond after the advancement of a bar into the mid position 38c following the energisation of contactor coil S5.
A pair of pneumatic balance cylinders BC are provided for balancing out the weight of the moving parts of the bar feeding elements 18 and associated mechanism, both of these being depicted in FIG. 6, and one of these being shown in FIG. 4, each cylinder being centrally trunnioned at 77 to base 25, and having the free end of the piston rod 78 fulcrummed to arm 79 connected to rock shaft 31, to which is connected to lower end of vertical link 29.
We claim:
1. Apparatus for effecting the controlled quenching of steel or other hot metal bars comprising:
(a) a bar receiving bank,
(b) means for advancing a succession of hot bars to the bank,
(c) a quenching bath adapted to contain the required quenching medium,
(d) bar supporting means movable between three different positions, namely a bar receiving position, a bar immersion position in which the bar is immersed within the quenching bath, and a bar discharge posi tion, in which the bar is discharged from said sup porting means,
(e) means for feeding the bars from the bank to the bar supporting means when the latter is in the bar receiving position, and so that the bars are fed successively thereto in the same order as that in which they are advanced in the heated state to the bank,
(f) a controlling device responsive to the temperature of each bar, arranged to initiate the movement of the bar supporting means after a bar has been fed thereto, into the bar immersion position to immerse the bar within the quenching bath when the temperature of the hot bar has fallen to a value corresponding to the required bar quenching temperature or range of temperature,
(g) means operated by said controlling device adapted to effect discharge from the apparatus without quenching of any bars fed or about to be fed to the supporting means at a temperature below the temperature, or below the minimum value of the temperature range, required for the bar just before quenching,
(h) a timing device arranged to control the duration of immersion within the bath of the bars by the supporting means, and
(i) means for effecting discharge of the quenched bars from the supporting means after their immersion in the quenching bath for the required period of time.
2. Apparatus according to claim 1, wherein the bar receiving bank comprises a series of bar locations spaced apart from one another in a direction transverse to the direction of bar feed to the bank, and the means for feeding the advancing bars to the bank comprises a bar transfer device responsive to the presence of a bar in the rearmost of the succession of bar occupied bank locations, so as to deposit the next successively advancing bar in the location next in rear (in the direction of bar advancement) to the location already occupied by the bar last fed thereto.
3. Apparatus according to claim 2, wherein the bar transfer device comprises a bar feeding element embodying a bar supporting part and a bar engaging part, which two parts are spaced relatively apart in a direction transverse to the direction or bar feed to the bank, by a distance corresponding to the transverse spacing between adjacent bar locations, the bar engaging part of the feeding element being adapted to engage and thus to sense a bar in an already occupied location and there be'ing means for displacing the bar feeding element in an orbital path to deposit the fed bar into an unoccupied location immediately in rear of the bar occupied location sensed by said bar engaging part, said bar feeding element being driven in its orbital path through a slippable clutch adapted to permit of the orbital movement of the bar feeding element, varying in accordance with the extent of occupation of the bank, as determined by the sensing action of the bar engaging part of the bar feeding element.
4. Apparatus according to claim 1, characterised in that the bar supporting means comprises two sets of bar retaining jaws relatively movable under the control of both the temperature responsive controlling device as well as under the control of the timing device between a closed bar retaining position and an open bar receiving and discharge position.
5. Apparatus according to claim 4, characterised in that the bar supporting means as a whole is movable under the control of said temperature responsive controlling device and timing device between two raised positions, namely a bar receiving position, in which the opening presented by the two sets of jaws is in the one case, namely the bar receiving postiion, directed towards the bank, and in the other case, namely the bar discharge position, directed towards a bar collecting trough or other collecting element to which the bars are discharged in a direction away from the bank, the bar supporting means being also adapted with the jaws in the closed position to be displaced into and out of a lower quenching position by the respective operation of the temperature responsive controlling device and the timing device.
6. Apparatus according to claim 1, wherein the arrangement is such that each bar irrespective of whether or no it is below the designed temperature is fed to the supporting means and the temperature responsive controlling device for effecting discharge of bars without quenching is so arranged as to be responsive to the bar temperature when the bar is on the supporting means.
7. Apparatus according to claim 1, characterised in that the means for feeding the bars successively from the bank to the bar supporting means comprises a walking beam device, the operation of which is actuated by means responsive to the presence or absence of a bar on the bar supporting means when in its bar receiving position, the arrangement being such that the walking beam operates to feed a bar to the supporting means when empty, each time this is in its bar receiving position and simultaneously feeds by one step, i.e. one location, in a forward direction any bars which have accumulated on the bank successively behind the foremost location previously containing the bar in course of being fed by the walking beam to the supporting means.
8. Apparatus according to claim 1, characterised in the provision of reject means responsive to failure of the jaws of the supporting means to move relatively into their closed position, as a result of more than a permissible departure of the bar from straight configuration, said reject means being adapted to displace the bar supporting means into the bar discharge position, and to effect relative movement of the jaws into their open position to discharge the rejected bar without immersion with the quenching bath, and means responsive to the operation of said reject means for diverting said rejected bar to a discharge position other than the position to which the quenched bars are discharged.
9. Apparatus according to claim 1, characterised in that the advancement of each bar through the apparatus including the quenching bath, is etfected by a series of fluid pressure operated rams, the control valves of which are actuated by solenoids, the energising coils of which form part of an electric circuit embodying a controlling pyrometer responsive to bar temperature, immediately prior to quenching, and to an electrically operated timing device controlling the duration of bar immersion within the quenching bath.
10. Apparatus according to claim 4, characterised in that the bar supporting means as a whole is movable under the control of said temperature responsive controlling device and timing device between two raised positions, namely a bar receiving position, in which the opening presented by the two sets of jaws is in the one case, namely the bar receiving position, directed towards the bank, and in the other case, namely the bar discharge position, directed towards a bar collecting trough or other collecting element to which the bars are discharged'in a direction away from the bank, the bar supporting means being also adapted with the jaws in the closed position to be displaced into and out of a lower quenching position by the respective operation of the temperature responsive controlling device and the timing device, said bar supporting means being mounted upon a rotatable shaft, the rotation of which serves to displace the bar supporting means between each of its several positions, the shaft being connected to a rack wheel which engages with a toothed rack connected to one of two piston rods of a double ram cylinder, the rod of the other piston of which is fixed to the base of the apparatus, the arrangement providing for the displacement of the ram cylinder relative to the fixed piston, or of the movable piston relative to the cylinder to vary the rotational position of the shaft carrying the bar supporting means.
11. Apparatus according to claim 1, characterised in that the timing device comprises an electric motor connected through an electrically controlled clutch to a wiper form of timing contact, with means to engage the clutch concurrently with the displacement of the bar supporting means in a direction to immerse the bar within the quenching bath.
References Cited UNITED STATES PATENTS 2,062,769 12/1936 Sprink. 3,103,939 9/1963 Haugland 13466 X 3,149,189 9/1964 Gogan 266-6 3,380,724 4/1968 Cary 2664 3,383,100 5/1968 Balzer et al.
J. SPENCER OVERHOLSER, Primary Examiner J. S. BROWN, Assistant Examiner US. Cl. X.R. 13 4-134
US612178A 1967-01-27 1967-01-27 Apparatus for use in effecting controlled quenching of metal in bar form Expired - Lifetime US3476371A (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2062769A (en) * 1933-06-22 1936-12-01 Logan Gear Company Quenching machine
US3103939A (en) * 1962-09-07 1963-09-17 United States Steel Corp Apparatus for immersing and draining pipe lengths
US3149189A (en) * 1960-05-06 1964-09-15 Gogan Joseph Bar quenching machine
US3380724A (en) * 1965-05-06 1968-04-30 Int Harvester Co Crankshaft induction hardening machine
US3383100A (en) * 1965-10-11 1968-05-14 Park Ohio Industries Inc Apparatus for hardening spaced bearing surfaces on a shaft-like workpiece

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2062769A (en) * 1933-06-22 1936-12-01 Logan Gear Company Quenching machine
US3149189A (en) * 1960-05-06 1964-09-15 Gogan Joseph Bar quenching machine
US3103939A (en) * 1962-09-07 1963-09-17 United States Steel Corp Apparatus for immersing and draining pipe lengths
US3380724A (en) * 1965-05-06 1968-04-30 Int Harvester Co Crankshaft induction hardening machine
US3383100A (en) * 1965-10-11 1968-05-14 Park Ohio Industries Inc Apparatus for hardening spaced bearing surfaces on a shaft-like workpiece

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