AU632337B2

AU632337B2 - Roller mill

Info

Publication number: AU632337B2
Application number: AU57907/90A
Authority: AU
Inventors: Murray John Parker; Timothy Francis Parker; Peter Scholz; William Somerfield
Original assignee: BONLAC FOODS Ltd
Current assignee: BONLAC FOODS Ltd
Priority date: 1989-06-27
Filing date: 1990-06-26
Publication date: 1992-12-24
Anticipated expiration: 2010-06-26
Also published as: AU5790790A

Description

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S32337

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority o, Related Art: 4 o Name(s) of Applicant(s).

Address(es) of Applicant(s): APPLICANT'S REF.: CAP of PJ 4941 BONLAC FOODS LIMITED Northern Region, Rushworth Road, Stanhope, Victoria 3623, Australia.

Actual Inventor(s): Address for Service is: PHILLIPS, ORMONDE AND FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne, Australia, 3000 2.

Complete Specification for the invention entitled: ACGTUATIN

APPARATU.S"

The following statement is a full description of this invention, including the best method of performing it known to applicant(s): P19/3/84 2 ROLLER MILL This invention relates generally to roller mills for cracking granulated product flowing along a product flow line. The roller mill is particularly applicable for installation in a livestock grain feed supply line, for cracking of grain feed prior to supply to the livestock. It will be convenient to hereinafter describe the invention in relation to that exemplary application, although it should be appreciated that the invention is not limited to that application.

Handling livestock grain feed typically involves storing the feed in a bulk container, such as a silo, from whAich the feed can be dispensed and conveyed on demand along feed conveyor lines to feeding bins or troughs. With grain feed it i' is usual to pass the grain through a roller mill which cracks the grain so as to facilitate digestion by the livestock.

That roller mill is generally stationed beneath the bulk I container so that the grain can flow under gravity from the Si! container, through the mill, to a conveyor line extending S.i' fo therefrom.

K In order to control flow through the roller mill and in I particular ensure grain does not "back up" within the mill, a i: valve assembly is installed in a flow line between the bulk container and roller mill. That assembly is actuable to K 5 selectively open and close the flow line. Actuation of the i valve assembly may be manual or through a variety of automatic i actuating arrangements. In one known actuating arrangement, an ope'able piston and cylinder actuator is connected to a valve closure member of the valve assembly. The cylinder is selectively connectable and disconnectable to a source of vacuum in order to cause a biasing force to be applied to the piston and thereby move that piston. That movement, in turn, opens and closes the valve closure member. In this arrangement, connection and disconnection of the vacuum is controlled through a separate solonoid valve, operation of which is initiated by a proximity switch located adjacent a feed transfer chamber extending between the roller mill and conveyor line. That proximity switch is located such that S sensing of the presence of feed is indicative of a feed level at which the valve closure member shou, close the flow line

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r 3 and so terminate feed flow through the roller mill.

Although this valve actuating arrangement is generally satisfactory, it is only of practical use where a source of vacuum is readily available, for example on a dairy farm close to a milking machinery facility. However, it is being increasingly recognised that grain feeding systems incorporating such arrangements have a much wider range of location and applicatio,,. Even then, proper operation of the actuator relies heavily on the integrity of the vacuum source, so that leaks in any connection can result in the incomplete opening or closing of the valve closure member.

It is an object of the present invention to alleviate these shortcomings of this valve actuating arrangement in a known roller mill through the provision of an improved roller .15 mill '1

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4 The present invention provides a roller mill for cracking animal grain feed flowing along a grain feed flow line, comprising: a roller set through which animal grain feed flowing along the flow line passes for cracking of the 20 feed; a valve assembly actuable to control animal grain feed flow through the roller set; and, apparatus for actuating the S valve assembly, the apparatus including an actuator connected to the valve assembly and electrically operable to actuate the S valve assembly between open and closed positions to control animal feed flow, and control means for operating the actuator, the control means having a proximity switch located .4 S adjacent the feed flow line to sense the presence or absence of animal feed, the control means responding to the sensing of the proximity switch to operate the actuator.

Preferably, the actuator includes a reversible electric drive motor operable in opposite drive directions. The control means preferably includes a switch device through which electric power is supplied to that drive motor. With this arrangement the switch device is operable to reverse drive motor polarity in order to operate the drive motor in opposite directions. The proximity switch is preferably connected to the switch device and responsive to tuie presence or absence of animal feed to cause operation of the switch device.

The switch device may include a switch relay operable r C ~3 4 between two switch positions for establishing alternative power line connections between the electric power supply and drive motor. To that end, the switch relay is biased into one switch position and the proximity switch is responsive to the preseiice or absence of animal feed to cause the switch relay to operate against the bias into the other switch position whilst the presence or absence of animal feed as sensed exists.

Preferably, the actuator includes a drive carriage reciprocally movable along a linear carriage path. That drive carriage is connected to the valve assembly for its actuation.

The roller mill preferably has a mill drive motor normally operable to rotate the roller set during roller mill use. Moreover, the control means preferably further includes a timer operable when the valve assembly is actuated to a closed position to maintain mill drive motor operation for a predetermined time period. The mill drive motor operation is then terminated if the valve assembly remains in the closed position at the end of the time period. Preferably, the control means includes a control device for controlling operation of the timer. That control device is responsive to the sensing of the proximity switch to cause enabling and disabling of the timer. The control device may include a control relay which is biased into a position enabling the timer. That relay operates against the bias into a position disabling the timer while the proximity switch does not sense the presence of animal feed.

oThe following description refers to a roller mill incorporating a preferred embodiment of the present invention, To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings where the roller mill is illustrated. It is to be understood that the invention is not limited to the embodiment as hereinafter described and as illustrated.

In the drawings: Fig. 1 is a side view of a roller mill according to a preferred embodiment of tht present invention; and, Fig. 2 is a schematic diagram of a valve assembly and actuating apparatus of the roller mill of Fig. i.

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In the drawingi: Fig. 1 is a id view a roller IO rp-r.gapparatus according to a preferrediment of the present invention; and, Fig. 2 i schematic circuit diagram of the apparatu2 Referring initially to Fig. 1 there is generally shown a roller mill M, installed beneath a bulk livestock grain feed container C, such as c silo, for receiving grain feed therefrom through delivery tube T. A conveyor line L, such as a conveying auger, leads away from mill M for delivering the grain feed to remote animal feeding bins or troughs (not shown). In general, grain feed flows under gravity from container C through roller mill M to convey line L located at the bottom of mill M, where i- is conveyed onto the feeding bins or troughs.

On passing through mill M, the grain feed is cracked to facilitate digestion by the livestock. To that end, mill M includes a roller set R, between which the grain is cracked, and a drive motor D connected through any sui'able drive transmission (not shown) to roller set R for rotating them.

Drive motor D is electric and operated by 240 volt AC mains power in this emLodiment. Roller mill M also includes a receiving hopper H beneath roller set R in which the cracked grain feed is collected for conveyor by conveyor line L.

Roller mill M further includes valve assembly V for controlling flow of grain feed from delivery tube T to roller set R. In this embodiment, valve assembly V is a gate valve assembly having a closure plate P linearly slidable in opposite directions to open and close the assembly V. It should be appreciated that in alternative embodiments other valve assemblies V, such as lift, ball or butterfly valve assemblies, may be provided.

Roller mill M incorporates apparatus 1 for actuating valve assembly V. Apparatus 1 can also control operation of drive motor D at least to some extent.

Apparatus 1 is shown in more detail in Fig. 2 and 39 includes linear actuator 2 having a linear drive output XW 5 'i-I connectable to valve assembly V. Actuator 2 includes drive member 3 reciprically movable to provide the linear drive output in opposite directions. In one embodiment (not shown) drive member 3 includes a drive rod longitudinally reciprocal in opposite directions, whilst in another embodiment (as shown) drive member 3 includes drive carriage 4 reciprocal~v moveable along a linear carriage path. Drive member 3 is connected directly (as shown) or indirectly (not shown) to valve closure plate P so that movement of drive member 3 in opposite directions opens and closes the valve assembly V.

Actuator 2 also includes electric drive means connected to drive member 3 and operable to move that drive member 3. Drive means 5 includes drive motor 6 connected to drive member 3, motor 6 being reversable to move drive member 3 in opposite directions. Drive motor 6 is a rotary drive motor in this embodiment.

Connection of drive motor 6 to drive member 3 is indirect, through drive transmission 7. Transmission 7 includes a drive screw and nut mechanism 8 for translating the rotary output of drive motor 6 into linear output of drive member 3.

Apparatus 1 also includes control means 9 for actuating actuator 2, and in particular drive motor 6. Control means 9 controls supply of electric power from a power source (not shown) to drive motor 6 for moving drive member 3. The power supply is a mains, or portable, or battery supply in alternative embodiments. In this embodiment, the power to drive member 3 is 24 volt DC power, although other power quantities are envisaged. In this embodiment, control means 9 includes power transformer 10 to convert a 240 volt AC mains power supply used to operate drive motor D into a derived power to operate drive motor 6.

In the case of a reversible drive motor 6, control means 9 acts to reverse motor polarity in order to cause motor 6 to move drive member 3 in opposite directions. That is achieved through switch device 11 interposed between the derived power supply and drive motor 6, and operable to interchange supply lines 12, 13 connecting the derived power supply and switch 39 device 11 with drive lines 14, 15 connecting switch device 11 6 C- I I I~ 1 ;i 1 and motor 6. Switchi device 11 includes switch relay 16 having two switch positions for establishing alternative power line connections between supply lines 12, 13 and drive lines 14, Relay 16 is biased, such as through a biasing spring (not shown), into one switch position, and operable against that bias into the other switch position. In this embodiment, the biased one switch position corresponds to drive motor operation which moves drive member 3 to close valve assembly V. Switch relay 16 is operated by energisable solenoid 17, in this embodiment.

Control means 9 includes blocking diodes and/or other components (not shown) to enable orderly supply of power to drive motor 6.

Control means includes proximity switch 18 located adjacent receiving hopper H to sense the presence or absence of grain feed and, in response to that sensing, initiate operation of switch device 11. Specifically, proximity switch 18 senses the presence or absence of a predetermined level of grain feed in receiving hopper H and causes control means 9 to set the switch relay 16 in a respective one of its switch positions. To that end, proximity switch 18 is ii .rposed between the derived power supply and solenoid 17, with positive line 19 cinnecting the power supply and switch 18 and positive line 20 connecting switch 18 and solenoid In this embodiment, when proximity switch 18 senses th -resence of feed at the predetermined level, switch re! .6 is operated through solenoid 17 into that switch position in which power moves drive member 3, and thus closure plate P, in one direction to close valve assembly V. When that feed is no longer sensed by proximity switch 18, because the feed level in the receiving hopper H has been reduced below the predetermined level, switch relay 16 is operated into the switch position in which power moves actuator 2 in a reverse direction to open valve assembly V.

In this embodiment, proximity switch 18 is a "normally closed" switch, remaining closed when feed is not sensed thereby energising solenoid 17 to move relay 16 against the bias causing drive motor ooperation which opens valve assembly 39 3. When feed is sensed by proximity switch 18, solenoid 17 is 7 de-energised allowing relay 16 to move under the bias to cause drive motor operation which closes valve assembly V.

Proximity switch 18 is a capacitive type in this embodiment.

Control means 9 is operable to vary the extent of movement (length of stroke) of drive member 3 in order to adjust the extent of valve assembly opening and closing. To that end, control means 9 includes one or more limit switches 21 arranged to operate, when drive member 3 reaches the end of each set stroke in either direction, to cease further 0to movement. Limit switches 21 operate in response to drive member or drive motor movement. Moreover limit switches 21 are moveable in order to vary the length of stroke of drive member 3.

Apparatus 1 also provides a connection between the mains power supply and drive motor D so that operation of valve assembly V and drive motor D are at least partially co-ordinated. In particular, control means 9 includes timer unit 22 interposed between the mains power supply and drive motor D, with lines 23, 24 connecting the power supply and timer device 22 and lines 25, 26 connecting timer unit 22 with drive motor D.

Timer unit 22 generally does not interfere with drive motor operation. However, when valve assembly V is actuated to a closed position by actuator 2, timer unit 22 operates to maintain drive motor operation for a predetermined time period. If, at the end of that time period, valve assembly V remains in the closed position then timer unit 22 operates to terminate drive motor operation by disconnecting drive motor D from the mains power supply. This delayed drive motor termination allows grain feed that has passed through valve assembly V to be cracked by roller set R and flow through to receiving hopper H.

Timer unit 22 includes timer 27 for setting the predetermined time period. Timer 27 may be manually adjustable to vary that time period. Typically, the time period may be about 30 secs. in the exemplary application of the apparatus.

Timer 27 is enabled and disabled by control device 28 39 connected to timer 27 through lines 29, 30, with control 8 IL I- device 28 being operably connected to the derived power supply through lines 31, 32. Control device 28 includes control relay 33 connected to the derived power supply through proximity switch 18, so that switch relay 16 and control relay 33 are connected in parallel with one another. Control relay 33 is operated by energisable solenoid 34 in this embodiment.

Relay 33 has two switch positions, respectively, enabling and disabling timer 27, and is biased, such as through a biasing spring (not shown), into one switch position and operable against that bias into the other switch position. In this embodiment, the biased one switch position enables timer 27 whilst the other switch position achieved against the bias disables timer 27.

Timer unit 22 further includes contact block 35 having terminals for interconnecting power lines 23, 24, 25, 26.

Contact block 35 normally provides a closed circuit between power lines 23 and 25, and 24 and 26, but is connected to timer 27 through lines 36, 37 for actuation thereby to provide an open circuit between lines 23 and 25 and 24 and 26. Thus, power from the mains power supply is provided to timer 27 through lines 23 and 36, which in turn is provided to contact block 35 through line 37 following enablement of timer 27 for a predetermined time period in order to operate contact block and provide the open circuit between lines 23, 24, 25, 26.

Control means 9 also Includes isolating switch 38 for selectively connecting the mains power supply to transformer for providing the derived power supply to operate actuator 2. Conveniently switch 38 is manually actuable.

-TIe ac--tuating apparatus of th- LpYe-eerf---iLUeL.o operates n electric power, which is generally more widely and readily avai ble than a source of vacuum as required to operate a prior ilar arrangement. As such, the apparatus of the present inv tion is expected to have greater application than the prio 'rrangement. In addition, the reliability of electric power iply generally tends to be higher than vacuum supply which, turn, should improve operating reliability of the apparat, of the present invention. That can be particularly im tant and a 3 W ignifi.cnt dantag inc- the apparatu- an -be xpe ce3 o- KW 9

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10 The actuating apparatus in the roller mill of the present invention operates on electric power, which is generally more widely and readily available than a source of vacuum as required to operate a prior similar arrangement. As such, the roller mill of the present invention is expected to have greater application than prior mills. In addition, the reliability of electric power supply generally tends to be higher than vacuum supply which, in turn, should improve operating reliability of the roller mill of the present invention. That can be particularly important and a significant advantage since the roller mill can be expected to operate for long periods of time without close attention or monitoring.

Finally, it is to be understood that various modifications and/or alterations may be made to the roller mill without departing fiom the ambit of the invention as defined in the claims appended hereto.

Claims

2. A roller mill as claimed in claim i, wherein the actuator has a linear drive output and is operable to provide Ea S a drive output in opposite directions to actuate the valve assembly between the open und closed positions. i2 3. A roller mill as claimed in claim 2, wherein the actuator includes a reversible electric drive motor operable S in opposite drive directions, and the control moans includes a switch device through which electric power is supplied to the drive motor, the switch device being operable to reverse drive motor polarity in order to operate the drive motor in opposite directions.
4. A roller mill as claimed in claim 3, wherein the switch device includes a switch relay operable between two switch positions for establishing alternative power line connections between the electric power supply and drive motor. A roller mill as claimed in claim 3 or 4, wherein the proximity switch is connected to the switch device and responsive to the presence or absence of animal feed to cause operation of the switch device.
6. A roller mill as claimed in claim 5 when appended to claim 4, wherein the switch relay is biased into one switch position and the proximity switch is responsive to the presence or absence of animal feed to cause the switch relay to operate against the bias into the other switch position whilst the presence or absence of animal feed as sensed exists. KW i2 12
7. A roller mill as claimed in any preceding claim, wherein the actuator includes a drive carriage reciprocally movable along a linear carriage path, the drive carriage being connected to the valve assembly for actuation thereof.
8. A roller mill as claimed in claim 7 when appended to any one of claims 3 to 6, wherein the electric drive -,tor is connected to the drive carriage to drive the drive carriage along the linear carriage path.
9. A roller mill as claimed in claim 8, wherein the electric drive motor is a rotatable electric drive motor and a drive screw and nut transmission assembly connects an output of the drive motor to the drive carriage. A roller mill as claimed in claim 3 or any clait. appended thereto, wherein the control means includes one or more limit switches operable to limit the extent of drive motor operation in the drive directions and thereby limit the S extent of valve assembly actuation.
11. A roller mill as claimed in claim 10, wherein the or each limit switch is movable to vary the extent of drive motor operation in a respective drive direction.
12. A roller mill as claimed in any preceding claim, and further including a mill drive motor normally operable to rotate the roller set during roller mill use, the control means further including a timer operable when the valve ,o5 assembly is actuated to a closed position to maintain mill drive motor operation for a predetermined time period and thereafter terminate mill drive motor operation if the valve assembly remains in the closed position at the end of the time period.
13. A roller mill as claimed in claim 12, wherein the l control means includes a control device for controlling operation of the timer, the control device responsive to the sensing of the proximity switch to cause enabling and disabling of the timer.
14. A roller mill as claimed in claim 13, wherein the control device includes a control relay biased into a position enabling the timer, the control relay operating against the bias into a position disabling the timer while the proximity switch does not sense the presence of animal feed. I r -J 'I 13 A roller mill for cracking animal grain feed flowing along a grain feed flow line, substantially as hereinbefore described with reference to the accompanying drawings. DATED: 16 October, 1992 PHILLIPS ORMONDE FITZPATRICK Attorneys for: BONLAC FOODS LIMITED A f A* 7211E