US2752647A

US2752647A - Foundry moulding machines

Info

Publication number: US2752647A
Application number: US329709A
Authority: US
Inventors: Beech Austin Sidney
Original assignee: Foundry Equipment Ltd
Current assignee: Foundry Equipment Ltd
Priority date: 1953-01-05
Filing date: 1953-01-05
Publication date: 1956-07-03
Anticipated expiration: 1973-07-03

Description

July 3, 1956 Filed Jan. 5, 1953 A. S. BEECH FOUNDRY MOULDING MACHINES 7 Sheets-Sheet 1 /N VEN 702 A. 6. BEECH MWMQ Filed Jan. 5, 1953 A. S. BEECH FOUNDRY MOULDING MACHINES 7 Sheets-Sheet 2 //v MFA/7'02 A. 6. 5650/ 2 mMWMQM Jufly 3, 1956 s BEECH 2,752,647

FOUNDRY MOULDING MACHINES Filed Jan. 5, 1953 7 Sheets-Sheet 4 lNl/f/YTOE 4 6. 5560/ MMQLQMMQ Juiy 3, 1956 A. s. BEECH 2,752,647

FOUNDRY MOULDING MACHINES Filed Jan. 5, 1953 7 Sheets-Sheet 5 //V VENTOZ A. 6. BEECH 2 mum Afravneus l July 3, 15556 A. s. BEECH 2,752,647

FOUNDRY MOULDING MACHINES Filed Jan. 5, 1953 '7 Sheets-Sheet 6 lNVf/VTOE A. 8. 5566/4 orn e56 3! 3, 1956 A. s. BEECH FOUNDRY MOULDING MACHINES 7 Sheets-Sheet 7 Filed Jan. 5, 1953 v VE/V me A. 3. BEECH Ammeys 2,752,647 FOUNDRY MOULDING MACHINES Austin Sidney Beech, Leighton Buzzard, England, assignor to Foundry Equipment Limited, Leighton Buzzard, England, a British company Application January 5, 1953, Serial No. 329,709 8 Claims. (Cl. 22-36) This invention relates to foundry sand ramming machines of the type comprising a swinging carrier-arm mounted to swing about a fixed axis and a ramming unit, comprising a motor and ramming head, pivoted on the end of the arm so as to swing thereon to any desired position over the foundry floor within its range.

Hitherto the carrier-arm has normally been mounted on a fixed upstanding column, about which it swung, and current for the motor on the ramming unit has been conveyed to the carrier-arm from the base by flexible cables According to the present invention the column, on which the carrier-arm is mounted, is made hollow, the electric supply connections are led into a fixed pedestal below the column, a motor-supply cable is mounted on the carrier-arm and connection between the electric supply and the cable is established through slip-rings on the column, electrical connections carried through the column which are connected to the slip rings at one end, brushes to engage the slip rings, and means joining the electrical connections on the one hand and the brushes on the other, the one to the supply and the other to the cable.

The brushes are located On the part which moves relatively to the column. This may be the carrier-arm, but preferably the hollow column is made rotatable in bearings in the pedestal, the carrier-arm is secured solidly to it, and the slip rings are located below the bearings, the brushes being located in the pedestal and joined to the supply, and the connection in the hollow column joined to the cable on the carrier-arm.

One of the advantages of the slip ling construction is that if adequate clearance is aitorded all round the pedestal from surrounding machinery or other objects, the carrier-arm can be rotated through 360 and may indeed be given repeated rotation, in which case the sand ramming machine can be set in the centre of a circle of moulding stations where operations of moulding are carried out seriatim on the lines of a mass production assembly, without necessitating the use of a turntable or mould conveyor.

swings and which is drive to the ramming head, in contradistinction to known constructions in which there is a triangulated beam having pivotal supports both above and below the motor drive. The carrier arm may comprise a plate beam which is located wholly below the drive between the motor and the ramming head and supports at one end a of the motor upstanding from the ramming head also upstanding from the beam, the pivot about which the beam swings being as before located entirely below the motor drive to the ramming head, and a gear box being located on the beam between the motor and the ramming head, and below the conveyor. In

A atent a seating for another other words, by reducing the depth of the beam it has been possible to locate the gear box on top of the beam Where it is readily accessible. It will readily be understood that this reduction of depth could not be accomplished but for the pivotal support of the beam being located entirely below the motor drive.

The invention further relates the motor constant as hereinafter more fully describedv The following is a description by Way of example of one form of sand ramming machine in accordance with the present invention.

In the accompanying drawings:

Figure l is a general side elevation of the machine;

Figure 2 is a section through the column of the machine, looking in the same direction as Figure 1;

Figure 3 is a detail of hopper-regulating arrangements looking in the direction of the arrow 3, Figure 1;

Figure 4 is a vertical section through the pivotal mount ing for the ramming unit;

Figure 5 is a section through the conveyor drive.

Figure 6 is an end view of the ramming head showing the control buttons;

Figure 7 is a plan of the gear box on the ramming unit, with the cover removed; and

Figure 8 is a diagram of pneumatic connections.

The machine comprises a cast iron pedestal it with an outwardly extending flange 12 around its bottom edge, which is the larger end of the cone. The flange is bolted on a base structure consisting of a plate 13 which rests upon two suitable spaced channels 14 and the channels extend along the ground level to a point at which they meet an upright framework 15 for carrying a sand-supply hopper.

In the drawings, the framework 15 will not allow the parts to swing through a complete circle, but it will be understood that the framework 15 can be made higher and spaced further from the pedestal for this purpose, if desired.

The pedestal casting 11 at its upper end is machined out to afford a seating for a large radial ball race 16, (Figure 2) and below the ball race the walls of the pedestal are re-entrant, that is to say they depend into the interior of the pedestal, forming a cylindrical internal boss 17 which is connected to the Walls of the pedestal by radial ribs 18. At the bottom end of the boss 17 is radial ball race 19, and column 20 is mounted on the ball races so that it can the upper to form a deep recess 29 shaped its side. Between the side plates there is welded a stiffening web 126 bent to conform to the notched-out recess 29. The inclined upper edges of the belt, are united by a skid plate 2.8 of the side plates are bent inwardly as shown at 30 so that they are nearer together than the main body of the side plates. Between the side plates at the bottom there is secured by bolting or welding a long horizontal box-shaped sheet metal arm 31, at the outer end of which is an upstanding fixedpost 32 to atford a bearing upon which the ramming unit 33 canswing. The general shape of the carrier-arm with the side plates 28 notched out as above described is somewhat like a distorted letter Gt.

At the bottomof the column there is secured to it below the lower ball race 19, a slip-ring assembly, consisting of thirteen insulated slip rings 41 co-axial with the column. This assembly is hollow and is bolted to the underside of a flange 45) carried by the column. The column itself is drilled up hollow -as shown in dotted lines at 42, to apoint'which lies within the above-mentioned square block 24 which spaces apart the side plates 26 of the carrier-arm. Electrical connections 41a in a conduit 41b are secured to the slip rings and carried up inside them and through the hollow column and thence through a lateral opening 43 (in the column and in the square block 24 which encircles it) to the back of the block, that is to say the sideaway from the laterally projecting carrier-arm 25. Here the connections enter a sheet metal terminal box 44 which is bolted on to the back of the block and are connected to a set of terminals (not shown in detail) on aterminal plate 45 made of insulating material. The top ofthe terminal box carries a socket 46 to receive the end of afiexible electric conduit 47. The conduit 47 contains a cable or cables for a conveyor motor 48. A second conduit 49, in which are supply and control wires for the electric motors of the machine, extends along the carrier arm and thence to the ramming unit 33 as hereinafter described.

The inclined upper edge of the carrier-arm supports a belt conveyor unit 50. The belt conveyor unit consists of two side plates 51, which are capable of being bolted to the top edges 23 of the carrier-arm plates 26, and which carry at their ends bearings 54, 55 for a conveyor belt 53 made of rubber and canvas. The conveyor belt 53 extends in an upwardly sloping direction from a point above the axis of the column 2% to a point nearly above the aforesaid stub bearing 32 for the ramming unit. The rear bearing 54 of the conveyor belt, above the column, is mounted in slides and provided with adjustment screws 56 and nuts to keep the belt in tension. The side plates 51 of the conveyor belt unit, above the upper stretch 57, and above the skid plate they carry upstanding side walls 58 of stout rubber, the lower edges of which bear on the rubber conveyor belt.

Two bridge members 60, 61 consisting of horizontal central portions and down-turned end portions, are secured across the conveyor unit towards the upper end thereof, the lower ends of the down-turned portions of the bridge members being bolted to the side plates 51 of the conveyor unit. The bridge members support rails 62 on which is mounted the electric motor 48. The motor is adjustable along the rails by screws 63 in known manner. The motor 48 carries a drive pulley for a \.'-belt 64- and a similar V-belt pulley on the roller spindle of the upper conveyor-bearing .55 is arranged in line with the motor pulley and connected thereto by the V-belt 64 so that the motor can drive the conveyor. A sheet rubber guard 65 forms a kind of hood around the delivery end of the conveyor and serves to guide material delivered by the conveyor downwardly on to the ramming unit 33. At the lower end of the conveyor 50 there is another sheet rubber guard 66 which tends to prevent moulding sand from being spilt when it is delivered on to the conveyor.

It will be noted that the above construction comprising the side plates, the conveyor belt, the motor and the hood all form a unit which can be quickly attached to the upper edges 28 of the carrier-arm, or detached therefrom, as desired. This unit can be separately as sembled and is therefore convenient in manufacture. The plate construction of the carrier arm and the inclined position of the upper edges thereof facilitates the provision of such a unit on the machine.

The upstanding framework 15 which has been already referred to and which is spaced from the pedestal 11, consists of two upright channel members, spaced apart and bent over at their upper end towards the axis of the column. Below the bent-over portion there are two horizontal channel members 70 which are secured to the two channel members 15 of the column, and which extend therefrom until they come nearly over the pedestal 11 and column 20. Here they are supported by angle iron straps '71 from the ends of the bent over portion of the framework. Above the horizontal channel members and between the channel members of the framework there is secured a moulding sand supply hopper 72. The horizontal channel members 70 form a platform which supports a horizontal belt conveyor 73 be neath the hopper, and the belt conveyor delivers moulding sand from the hopper on to the conveyor unit 50 which is mounted on the carrier-arm. In front of the conveyor belt 73, where it delivers 'from the hopper, is a rubber guard 273 which cooperates with'the guard 66 to prevent spillage of sand delivered. by the conveyor.

he belt conveyor 73 beneath the hopper is driven by a geared electric motor 74 secured to the front of the hopper, through a chain drive in a casing 75,-and the electric motor 74 is provided with connections which extend to certain of the slip rings 41 on the slip ring assembly at the bottom of the column 29.

The slip ring assembly -41 has bearing upon it a number of contact brushes '76 which are mounted on a contact-brush assembly 77 located in the base of the periestal and including an insulating plate which is bolted to the back of a terminal'box 79 in the pedestal. The terminal box has a flat access cover 78 which is vertical and is bolted to a flat vertical rectangular flange formed by appropriately moulding one side of the conical-pedestal 11. In the access cover is a socket or sockets '192 for electric conduits to the main supply and to connections to the conveyor motor 74. The hopper motor is controlled by push buttons on a-box 80 on the ramming head connected through-the conduit 49 andslip rings 41 so as to be convenient to the operator.

As shown in Figure 6 the push buttons on box 80consist of two

starter buttons

113, 114, the first for the conveyor motor 74 and thesecond for the two motors 48, 8? on the carrier arm and ramming unit. There is a single stop button which stops all the motors. in addition there are three pneumatic speed-control and gate-

control buttons

116, 117, 217 for the pneumatically operated gate of hopper 72 and gear box 94, hereinafter described.

At the outlet from the hopper 72 above the belt 73 is a sliding gate 81 (Figure 3) operated by two

air cylinders

130, 230 in tandem. The cylinder .130 is fixed to the framing which carries the hopper 72 and it contains a piston and piston rod 131 which enters the second cylinder 230 and operates a piston 132 therein. The cylinder 230 is movable, being secured by nuts 133 to an angle member 134 on the gate 81. Allthese parts can also be seen in the pneumatic connection diagram, Figure 8, and their control is hereinafter described in connection therewith. The fixed cylinder l1as astroke equal to one half of the movable cylinder 230 and the combined stroke of the two cylinders is equal to the total desired travel of the gate 81.

The ramming unit consists of a frame 33 which carries at one end an overhung electric motor 89 and at the other end the ramming head-90. The motor and the head are balanced about the aforementioned upstanding 'stub spindle 32 on the carrier-arm 25, and the frame carries 75 a detachable conveyor unit 91 for conveying sand from d the conveyor on the said carrier-arm to the ramming head. It will be understood that in Figure 8, which is a diagram only, the two

conveyors

50 and 91 are shown coalesced into one.

At its outer end the box-shaped girder 31 is pierced with a large aperture in its top plate 35 in which is bolted a cross-member 82 supporting a stub axle 32 (Figure 4).

' upwardly and carries roller The a casting 85 which provides of side plates 86, and a large angles to the side plates for motor 89. The plates 86 are they are secured to the casting races 83, 84 are housed in lateral faces for the support vertical flange 88 at right the support of an electric Widest at the part where on which it swings.

The ramming head contains a twin-bladed impeller in the casing 90 which the interior of the ramming head casing is known per se. The motor shaft 93 of the motor is connected to the impeller shaft 92 through an intermediate gear-box 94 and

couplings

194, 195. It is to be end of the gear box 94. Within the sleeve 196 are needle bearings for a shaft 198 which runs right through the gear box and is supported in the other end wall by a ball bearing 199. On the inner end of the sleeve 198, within the gear box, there is secured a gear wheel 200 which meshes with the gear wheel 201 on a lay shaft 202 carried on ball bearings 203, 204 so as to extend parallel with the shaft 198. The other end of the lay shaft carries a pinion 295 which meshes with a gear wheel 206 free to rotate on needle bearings 207 on the shaft 198. The gear wheel 200 carries an axially extending sleeve 208, the end of which has dog teeth to engage plate member 209 of a plate clutch. Alternating with the plate members 209 are intermediate plate members 210 which are slidably keyed to an enlarged central portion 211 of the shaft 198. A pressure ring 212 around the portion 211 of the shaft 193 lies between the plates 210 of being moved along the shaft by crank arms 214, 215 carried on a rock In a similar way the gear wheel 2116 carries an axially projecting sleeve 218 having dogs 219 which engage clutch plates 220 alternated with other plates 221 which are keyed to the shaft 108. These plates can be pressed together by a pressure ring 212 surrounding the part 211 of the shaft 198 on the opposite side of the collar 213 on the pressure ring 212. The effect is that if the rock shaft 216 is rocked in one direction, to move the collar 213 to the left as viewed in Figure 7, it will press the

plates

209, 210 of the left-hand clutch together and cause the sleeve 196 to drive the shaft 193 directly.

If the rock shaft 216, however, is rocked in the other direction, to move the collar 213 to the right as viewed in Figure 7, it will press the

clutch plates

220, 221 together and cause the gear wheel 206 to drive through the gears 200, the coupling 195 at a reduced speed.

The rock shaft 216 extends through bearings in the wall of the gear box 194 and carries a crank arm 214 which is operated by a ram 225 belonging to the gear box control cylinder 150 which has been already referred to.

Referring now to Figure 8, the cylinder is connected by

pipes

135, 136 to a valve box 137 located close to it on the hopper, and the cylinder 230 is connected by

pipes

235, 236 to a valve box 237. The

pipes

235, 236 are flexible to permit of movement. Air under pressure to move the gate is supplied to the valve boxes 137, 237 by supply pipes 238, and control of the gate is efiected by three

control pipes

240, 241, 24-2 which extend from the hopper to the base 11 of thecolumn and thence as shown in Figure 2 through the column to the arms which support the ramming head alongside the electric cable 49 to a control box 239 on the ramming head which carries the

push buttons

116, 117 and 217. Air is supplied to these push buttons through a pipe 243. Each push button comprises a valve casing containing a piston valve 244, 245 and 246 respectively. The valves are moved by springs 254, 255, 256 respectively to the forward position Where they connect

pipes

249, 241, 242 to the atmosphere, but if any push button is pressed in, the corresponding pipes are connected to the supply pipe 243.

The push button 116 may be called the high speed push button. It has a branch 248 to the gear change cylinder on the gear box 94, and when it admits air to the pipe 24-1 it simultaneously moves the gear in the gear box 94 to the high speed position. Simultaneously air from the pipe 241 enters the upper end of the valve box 237 and moves the is the low speed push button and moves the valve 245 to admit air to the pipe 242 and raise the This moulds and so forth. The push button 217 will there fore be referred to as the minimum output push button.

mum output eflect, if such be in Again pressing button 217 will however restore it again, if desired.

The interlock v'alve box 252 contains a spool 258, normally urged by a spring 259 to the position which pipes,257, 253 are in communication with one another. It is desired that operation of push button 117 shall also restore the minimum output cylinder 130 to its normal position. To this end a branch 260 from pipe 242 oper ates a piston 261 on spool 258, to lift the spool against spring 259 and admit air from pipe 238 to pipe 253 and so giving the effect desired.

As the

pneumatic push buttons

116, 117, 217 are returned after the operator ceases to press on them, by their springs, while the effect of their operation remains till another push button is pressed, it is desirable to indicate to theoperator which push button was last operated. To this'end,

indicator lamps

276, 277 and 287 (Figure 6) are disposed alongside the buttons on the head and operated by suitable electrical. connections from contacts actuated by the push buttons.

.In operation, assume that the lower push button 117 ispressed, causing the pipe 242 to operate spool 249 toadmitair pressure to the pipe 236. The cylinder 150 will also 'be supplied through the branch 250 with air under pressure and will move the gear box rock shaft 216 in such a direction as to engage the clutch plates .220, 221 and drive the ramming head at the lower speed. At the same time the cylinder 230 will .be operated to raise the gate 81 and the full delivery of sand will take place.

The drive for the two

conveyors

50 and 91 and the driving motor 89 for the ramming head is then set in motion by operating the

appropriate push buttons

113, 114 on the ramming head, and sand is thrown from the ramming head outlet downwards into a mould which requires to be rammed and has been placed below the head.

When the character of the mould makes it advisable to throw sand at higher speeds into certain parts, the push button 116 is pressed and causes the valve 244 to move over and pass compressed air to the pipe 241 and branch 248. Thereby the gear box control cylinder .150 is caused to move over the rock shaft 216 and change the gear to a direct drive through the shaft 198. thus increasing the speed of the impeller, while at thesame time the gate 81 is moved downwardly by the cylinder 230 so that the quantity of sand is reduced. Thereby,

the load on the motor 89 is kept approximately constant and a smaller amount of sand is rammed at the higher speed into the mould.

The tendency for the load on the driving motor to increase by reason of the high speed of delivery of the sand from the rammer head 90 is oilset by the reduction in the quantity of sand caused by the simultaneous lowering of the hopper gate 81. In either case, additional operation of button 217 wlil reduce the sand delivery without altering speed.

Preferably, the gear box 94 and the drive for the conveyor are enclosed by hinged side plates which may be hinged down out of the way when the parts need attention. These are not shown in the drawing.

The driving coupling 195 of the gear box is connected to the shaft 92 of the rammer head which passes through a gear casing 95 (Figure containing a bevel gear 109 to drive a laterally projecting shaft 110 which carries a sprocket 111 for driving a chain 112 which operates a sprocket 103 on a shaft 102 carrying a driving roller 99 for the conveyor 91. Thus, the conveyor 91 and the impeller in the rammer head 90 both have their speeds changed whenever the gear box is operated.

Although the gear box described above is only a two speedgear box, it will be understood thatathree or four speed gear box may be provided, with suitable automatic control, in accordance with the invention. In some cases it may be desirable to vary the supply of sand at a particular rammingspeed so as to-give less than the amount of .sand which corresponds to the normal load on the motor. To this purpose there may be providedan additionalpush button on the ramming head to vary the speed of the motor 74 which operates the .conveyor 73 and reduce the delivery of sand without interfering with the rate of operation of the motor 89 or the gear box 94.

The push button 115 on the ramming head is a stop push button,;pressure on which will immediately stop both the motors and bring the machine to rest. Conveniently, also, this is connected with a contact operated if the door,'hinged at 183 on the ramming head, is opened. it thus becomes impossible to start the machine with the ramming head open. The handles 187 serves both to manipulate the ramming head in use and to open the door when the wing nuts 188 are undone.

I claim:

1. A. foundry sand-ramming machine comprising in combination a ramming-head, means for supporting the ramming head so that it can be moved over a mould, a ramming-head motor, a gear-box interconnecting the motor and ramming-head, a sand supply hopper, conveyormeans between the hopper delivery and the ramminghead, regulating-means for'the hopper delivery, and control means for the gear-box interlinked with the regulating-means for the hopper delivery so that when the gear is changed to low the hopper delivery is increased and when the gear is raised the hopper delivery is decreased.

2. A foundry sand-ramming machine having a ramming assembly comprising, a beam pivoted upon a swingable carrier-arm about a vertical axis which passes approximately through the centre of gravity of the assembly, a ramming head on one end of said beam, a ramming head motor on the other end of said beam and a gear box between the motor and head, said machine also having a moulding-sand hopper, delivery-regulating means for the hopper to vary the rate of delivery of moulding sand therefrom, conveyor means to deliver sand from the hopper to the ramming head, gear-change means for the gear box and control-means for the gear-change means which is operatively connected to the delivery regulating means for the hopper so that when the gear is changed to low the hopper delivery is increased and vice versa.

3. A foundry sand-ramming machine as claimed in claim 2 wherein the ramming assembly comprises side plates hinged on each side of the beam and capable of being secured to the sides of the conveyor which is supported on the ramming assembly, so as to enclose the motor and gear box. I

4. A foundry sand-ramming machine as claimed in claim 2 wherein the hopper is supported on an overhang ing bracket from a frame upon which the swingable carrier arm is also mounted.

5. A foundry sand-ramming machine having a ramming assembly comprising, a beam pivoted upon a swingable carrier arm supported-on a rotatable column, which column is mounted on a fixed pedestal and motor connections are taken from the main supply into the pedestal and through the column by way of slip-ring and brush assembly in the pedestal coaxial with the column the pivot point of the said beam passing approximately through the centre of the assembly, a ramming head on one end of said beam, a ramming head motor on other end of said beam and a gear box between the motor and head, said machine also having a moulding-sand hopper, delivery-regulating means for the hopper to vary the rate of-delivery of moulding sand therefrom, conveyor means to deliver sand from the hopper to the ramming head, geanchange means for -the gear box and control-means for the gear-change means which is operatively connected to the delivery regulating means for the hopper so that when the gear is changed to low the hopper delivery is increased and vice versa.

6. A foundry sand-ramming machine comprising in combination, a pedestal, a column rotatably mounted in, and upstanding from, the pedestal, a carrier-arm extending laterally from the column above the pedestal, sheet metal sides on-the'carrier arm extending upwardly therefrom, a conveyor supported by said sides so that one end overlies the axis of the column and the other end overlies the end of the carrier-arm, an upstanding pivot on the carrier-arm and a beam mounted on the pivot, a ramming-head on one end of the beam, a ramming-head motor on the other end of the beam, a gear box on the beam between motor and ramming-head, gear-change means for the gear box, a second conveyor above the gearbox, one end of the second conveyor being located to receive sand from the conveyor on the carrier-arm, the assembly of head, motor and conveyor on the beam being balanced about the pivot, an automatic-delivery hopper to deliver sand at a predetermined rate to the conveyor on the carrier arm delivery-regulating means are provided to vary the rate of delivery of sand by the hopper, and the delivery-regulating means are interconnected with the gear-change means to be operated simultaneously therewith.

7. A foundry sand-ramming machine having a ramming assembly comprising a movable support, a ramming head, a ramming head motor and a gear box between the motor and head on the support, the support being movable to bring the head over any desired part of a mould, said machine also having a hopper, delivery-regulating means for the hopper to vary the rate of delivery of moulding sand therefrom, means to convey sand from the hopper delivery to the ramming head, gear-change References Cited in the file of this patent UNITED STATES PATENTS 1,335,641 Beardsley et al Mar. 30, 1920 2,212,510 Clay et al. Aug. 27, 1940 2,339,001 Clay et al Jan. 11, 1944 FOREIGN PATENTS 646,185 France July 10, 1928 570,641 Great Britain July 16, 1945

Claims

1. A FOUNDARY SAND-RAMMING MACHINE COMPRISING IN COMBINATION A RAMMING-HEAD, MEANS FOR SUPPORTING THE RAMMING HEAD SO THAT IT CAN BE MOVED OVER A MOULD, A RAMMING-HEAD MOTOR, A GEAR-BOX INTERCONNECTING THE MOTOR AND RAMMING-HEAD, A SAND SUPPLY HOPPER, CONVEYORMEANS BETWEEN THE HOPPER DELIVERY AND THE RAMMINGHEAD, REGULATING-MEANS FOR THE HOPPER DELIVERY, AND CONTROL MEANS FOR THE GEAR-BOX INTERLINKED WITH THE REGULATING-MEANS FOR THE HOPPER DELIVERY SO THAT WHEN THE GEAR IS CHANGED TO LOW THE HOPPER DELIVERY IS INCREASED AND WHEN THE GEAR IS RAISED THE HOPPER DELIVERY IS DECREASED.