US3357648A

US3357648A - Mixer-grinder for foundry sand

Info

Publication number: US3357648A
Application number: US429045A
Authority: US
Inventors: Yeomans Lena Sarah; Ronceray Andree Jacqueli Laure; Ronceray Francoise Moniqu Mary; Ronceray Pierre Robert
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-02-14
Filing date: 1965-01-29
Publication date: 1967-12-12
Anticipated expiration: 1984-12-12
Also published as: BE657072A; GB1035582A; ES308072A1; FR1393565A; CH430957A; DE1433989A1

Description

Dec. 12, 1967 R, A. M. RoNcx-:RAY

MIXER-GRINDER FCR FOUNDRY SAND 2 Sheets-Sheet 1 Filed Jan. 29, 1965 SNN Q Dec. l2, 1967 R. A. M. RONCERAY Y 3,357,648

MIXER-GRINDER FOR FOUNDRY SAND 2 Sheets-Sheet 2 Filed Jan. 29, 1965 United States Patent O 3,357,648 MIXER-@KINDER FOR FOUNDRY SAND Robert Andr Marcel Ronceray, 122 Ave. des Champs Elysees, Paris 8, France; Lena Sarah Yeomans, Andree Jacqueline Laure Ronceray, Franoise Monique Mary Ronceray, and Pierre Robert Roncel'ay, heirs of said Robert A. M. Ronceray, deceased Filed Jan. 29, 1965, Ser. No. 429,045 Claims priority, application France, Feb. 14, 1964, 963,8l9 4 Claims. (Cl. 241-110) ABSTRACT F THE DISCLOSURE A mixer-grinder has a pan of relatively substantial depth mounted to rotate about a central shaft which is stationarily mounted on a frame. A unit is stationarily mounted on the upper extremity of the shaft and the unit has a feed hopper for supplying material to the pan close to the center thereof. One or more axles are stationarily mounted on the unit above the pan and a muller of ovoid longitudinal cross section is mounted to rotate freely on each axle. An arm is stationarily mounted on the unit parallel to its associated axle and each arm supports a plurality of discs which can be separately oriented.

The present invention has for its object a mixer-grinder for foundry sand, that is to say a device which is intended to effect the intimate mixture of the sand with the different addition products which are usually contained in foundry sand. The mixture thus obtained will be referred to hereinafter as sand. rPhe operation which the said device is intended to'perform not only entails a simple mixing process but also the grinding of the particles which form the nal mixture.

It has already been proposed to construct devicesy of this type which comprise a rotatably driven tray for receiving the sand to be processed; there being placed within said tray mullers for crushing the sand and breaking up the lumps which may be present: provision is also made for at least one and preferably two series of discs which are mounted on approximately radial arms and the intended function of which is to facilitate the mixing of the constituent materials.

However, the devices of this type which havealready been produced are attended by certain disadvantages which it is precisely the aim of this invention to circumvent.

In particular, the above-mentioned tray has been designed up to the present time in the form of a relatively shallow casting which is driven in rotation as a result of the cooperation of a toothed ring rigidly fixed to said tray with a pinion which is mounted on a driving shaft. This arrangement entails the need to machine the tray which cannot be employed in the as-cast state and it is observed that, in spite of this precaution, the device generates a high level of noise and produces powerful vibrations which result in premature wear.

The present invention has for its object a device of this type in which the sand circulates continuously, that is to say in which the supply of sand to be processed as well as the discharge of processed sand takes place in a continuous manner.

The device in accordance with the invention comprises in combination a pan of relatively substantial depth in which are mounted the grinding and mixing devices, a feedhopper which is intended to be continuously supplied with sand which is conveyed by said hopper in the vicinity of the center of the pan, at least one ovoid muller which is mounted parallel to the radius of the pan, and at least ICC one peripheral outlet which permits the discharge of processed sand and which is associated with a deflector device for bringing the peripheral layer of sand into said discharge outlet.

In accordance with one characteristic feature of said device, the pan is supported at the center by a stationary shaft and carried on at least two wheels tted with tires on which said pan rests, at least one of said wheels being mounted on an axle which is driven positively in rotation.

ln an advantageous form of embodiment of the invention, the rotary axle referred to is the output shaft of a motor and more advantageously of a reduction gear motor, with the result that the tire is directly driven in rotation.

In another advantageous form of embodiment of this invention, the ovoid muller is mounted to rotate freely on an axle which is substantially parallel to the radius of the pan but which is displaced to the rear of said radius relatively to the direction of rotation of the said pan.

Vertical discs are mounted in front of each of the mullers which are preferably two in number and on a supporting arm parallel to the arm which carries the muller, the plane of said vertical discs making a variable angle with the shaft on which said discs are mounted.

It will be noted in particular that the device in accordance with the invention is not provided with any stationary scraper, such scrapers being replaced by the above-mentioned discs which are capable of motion; the result achieved by this arrangement is that wear is distributed over a greater length (external diameter of the discs), which accordingly reduces the rate of wear, requires less Vfrequent adjustments and, in addition, achieves more effective mixing of the sand as a result of a more powerful stirring action.

In a particular form of execution of the assembly of the aforesaid discs, each disc referred to is mounted elastically with respect to the shaft which supports the combined assembly of discs of one series, in such a manner that the discs are lifted when a hard foreign body passes accidentally into the apparatus; this arrangement prevents the destruction of the discs.

The angle which is made by the line at right angles to the plane of the discs with the axis of the shaft which carries said discs is such that the sand is brought back towards the mean radius of the pan; since the resultant action of the ovoid profile of the mullers, the portion of kgreatest thickness of which is located precisely in said means radius, is exerted in the opposite direction, there are thus obtained two actions which oppose each other to a certain extent.

It is thus possible to modify the angle of inclination of each disc in order that the centrifugal motion has a slight preponderance which is sufcient to ensure that the mixture of sand is homogeneous and aerated when said mixture reaches the periphery of the pan so as to be discharged.

Further characteristic features of the invention will be brought out by the following description, reference being made to the accompanying drawings which are given by way of example without implied limitation, and in which:

FIG. 1 is a view in elevation and in substantially diametrial cross-section of an apparatus in accordance with the invention;

FIG. 2 is an overhead plan view;

FIG. 3 is a detail view which illustrates the assembly of the discs on the shaft which supports these latter.

The apparatus in accordance with the invention is mounted on a frame 1 which is of circular configuration, for example, to which is secured a central vertical shaft 2 for the purpose of supporting and centering the pan 3.

As will be apparent especially from FIG. 1, the said pan is of relatively substantial depth and rests on wheels such as the wheel 4, each wheel being fitted with a tire 5, 5a which is inflated with air at a pressure which is determined by experiment.

The half-axles such as 6 on which the above-mentioned wheels are mounted are each carried on a plate 7 which has in cross-section the shape of a T with unequal arms. The longest arm or upper arm of the T receives the corresponding half-axle and the lower arm 8 rests on the frame 1 to which the central perpendicular arm 9 is fixed in any suitable manner, for example by means of a bolt or screw 10.

An individual reduction gear motor such as the motor 11 and the motor 12 is mounted on the half-axle 6 of at least one and preferably two wheels tted with tires, with the result that the said wheels communicate the movement of rotation of the axle to the pan 3; this arrangement has a large number of advantages and in particular the following: by virtue of the presence of the tire combined with the weight of the pan 3 and its contents, the driving of the pan in rotation is carried out without slippage and, in addition, this driving motion is essentially noiseless. Furthermore, the tires permit the possibility of employing an as-cast pan since they absorb any roughness of the outer surface of said pan, so that the driving motion is performed noiselessly and without vibrations.

The pan 3 is mounted on the shaft 2 through the intermediary of the sleeve 13 and nut 14 between which is interposed a tapered roller bearing, thereby avoiding any appreciable tilting of the pan if one of the tires were to become deflated. It is additionally observed that the said tapered roller bearing is perfectly unobstructed and very easy of access from the exterior, with the result that the positional adjustment of the pan relatively to the shaft 2 is greatly facilitated.

As will be understood, it is within the scope of this invention to provide a number of wheels which is sufficient for the purpose of ensuring perfect balancing of the pan. For example, provision can be made for three wheels which are spaced at an angle of 120 from each other. However, as will also be understood, it is not essential that all of the wheels thus provided should be driving wheels. On the contrary, a certain number of such wheels can be mounted to rotate freely in such a manner as to perform solely a supporting and guiding function.

There are mounted in the interior of the pan 3 two

mullers

15 and 16 which are distinguished by their ovoid shape and the maximum diameter of which, located at approximately one half the length thereof as shown at 17 in the case of the muller 16, is located virtually at the level of the mean radius of the pan 3. The ovoid shape of said mullers makes it possible to set these mullers at a distance from the pan which can be made to decrease according to any given law and in as progressive a manner as may be desired. The result thereby achieved is that there is obtained in a simple manner an increasing compression of the sand as the sand is displaced towards the periphery of the pan.

The axle such as 18 on which the muller 16 is mounted is substantially parallel to the radius 19 of the pan but is displaced to the rear as shown in FIG. 2 in the case of the axis 20 relatively to the direction of movement of the pan which is indicated by the arrow F. The result of this arrangement is to permit a radial sliding movement of the sand beneath the mullers and a better attack of the sand which, as has been observed from experiment, passes beneath the mullers without drifting in front of these latter.

The half-axles which support the

mullers

15, 16 are mounted on a kind of yoke 21 which, as shown more especially in FIG. l, is :mounted astride the sleeve 13 around the exterior of this latter and carried on roller bearings which are fitted in the interior of said sleeve 13 and at least one of which is a tapered roller bearing.

The two half-

shafts

22, 23 which carry the discs 24, 25,.

26, 27 and 28 are also mounted on the ends of the yoke 21 on each side of the vertical shaft 2. The discs referred-to are freely mounted in the manner which will be indicated below and are intended to work and aerate the sand while at the same time distributing the sand in a suitable manner in front of the muller.

The line at right angles to the plane of each disc makes an angle a with the axis of the shaft 22 which is variable according to the disc considered.

By way of example without any limitation of the invention being thereby implied, the angle a relative to the disc 24 can be chosen equal to approximately 43; the angle a relative to the disc 25 can be equal to approxi- -mately 33; the angle a relative to the disc 26 can be equal to approximately 27, and so forth in sequence up to the angle made by the disc 28, which can be of the order of 5.

The discs which are mounted on the shaft 23 make an angle a which is of substantially the same order, the discs which are symmetrical with respect to the shaft 2 having substantially the same angle of slope. However, it will be noted that provision is made for an additional disc 29 to which there corresponds an angle a of the order of 13, but the slope of which is in a direction opposite to that of the other discs, as can clearly 4be seen from FIG. 2. The intended purpose of said disc 29 is to bring back the sand located at the periphery towards the corresponding muller 15.

Similarly, provision is made for a disc 30 which is associated with the shaft 22 so that the line -at right angles to the axis of symmetry of said disc makes an angle of approximately 13 with the axis of said shaft, said disc being placed in such a manner as to direct the Sand towards the discharge chute 31. 'To lthis end, said disc 30 is orientably mounted on a shaft 32 which is in turn carried by an arm 33, said arm being pivoted on the shaft 22.

It will be understood that, depending on the nature of the sand, it will be possible to modify the angle made by each disc with the axis of the shaft on which said disc is carried.

FIG. 3 shows the manner in which the discs are supported by a shaft such as the shaft 22.

There is rst of all provided a ring 34 which is keyed on the shaft 22, for example by means of the screw 35; said ring is associated with a ring 36 which is loosely mounted on this same shaft, the two

rings

34, 36 referred to being connected by means of a spring 37, one end 38 of which is fitted within a blind-end bore of the loose ring 36; the other end of the spring is designed to penetrate into a recess 39 of the adjacent `loose ring 42 after lhaving been passed through an opening of the fixed ring 34; a screw 41| which is screwed into said adjacent loose ring 42 is brought to bear -against the corresponding extremity 41 of the spring which is located within the recess 39. The extremity 41 of the spring therefore serves as a fixed bearing point for said spring and at the same time serves as a bearing member about which the abovementioned loose ring 42 can be oriented.

The discs are mounted on vertical rods, this assembly being carried out in -a known manner, the said rods being each inserted in an opening such as the split collar 43 which is formed in each of the loose rings. It is therefore possible to vary the orientation of the plane of the disc relatively to the shaft 22 by slackening off the nut 44 which is mounted on the bolt 45.

Should a hard object fall accidentally into the pan and reach the level of the discs, the disc or discs encountered by such an object can be lifted by causing the loose ring 36 to rotate -in opposition to the spring 37; the hard object wil-l thus pass Without causing damage beneath the line of discs, the disc or discs thus lifted being then returned to the initial position as a result of the action of the spring or springs.

The adjustment of the screw 40 which is applied against the fixed extremity of the spring permits the possibility of adjusting the initial angular keying of the loose ring with respect to the shaft 22. Finally, the length of the recess 39 is a measure of the possible displacement of the disc in the vertical direction. Thus, referring to the disc connected to ring 42, if this disc is displaced upward-ly, the ring 42 will rotate about the axis of shaft 22 until the lower end wall of recess 39 abuts against the extremity 41 of the spring 37 to limit further rotation of said ring and thereby prevent further upward displacement of the disc mounted on said ring.

The sand to be processed is continuously fed in through the hopper 46, that is to say near the center of the pan 3 and is subjected to the action of the mullers and of the discs. The sand is then discharged through the discharge chute 31 by means of the disc 30.

What is claimed is:

1. Mixer-grinder for foundry sand comprising in combination a central shaft stationarily mounted on a frame, a pan of relatively substantial depth which is mounted to rotate yfreely on said shaft, 'a radial unit stationarily mounted at the upper extremity of said shaft, a feedhopper centrally carried by said unit and provided with a conduit which has its opening close to the center of the pan, two half-axles stationarily mounted on said unit 4and extending in opposite directions from said unit at right angles thereto, a muller of ovoid longitudinal -cross-section mounted to rotate freely on each of said half-axles, two arms stationarily mounted on said unit and each arm being parallel to the half-axle which is located on the same side of the stationary unit as said arm, discs mounted on each of said arms in separately orientable manner, a discharge chute located at the periphery of said pan, a decctor orientably mounted at the extremity of that arm which is adjacent said discharge chute, and means for rotating said pan.

2. Mixer-grinder for foundry sand comprising in combination a central shaft stationarily mounted on a frame, a pan of relatively substantial depth which is mounted to rotate freely on said shaft, a radial unit stationarily mounted on the upper extremity of said shaft, a feedhopper centrally carried `by said unit and provided with a conduit which opens near the center of the pan, two half-axles stationarily mounted on said unit and extending in opposite directions from said unit at right angles thereto, a muller of ovoid longitudinal cross-section mounted to rotate freely on each of said half-axles, two arms stationarily mounted on said unit and each arm being paraldel to the half-axle which is located on the same side of the stationary unit as said arm, discs mounted on each of said arms in separately orientable manner, a discharge chute located at the periphery of said pan, a deiiector which is orientably mounted at the extremity of the arm which is located near said discharge chute, at least two wheels fitted with tires and mounted on the Iframe, a reduction gear motor set carried by said frame, at least one of said wheels being keyed to the output shaft of said reduction gear motor set, and the pan being carried 0n said wheels.

3. Mixer-grinder for foundry sand comprising in combination a central shaft stationarily mounted on a frame,

a pan of relatively substantial depth which is mounted to rotate freely on said shaft, a radial unit stationarily mounted at the upper extremity of said shaft, a feedhopper centrally carried by said unit and provided with a conduit which has its opening close to the center of said pan, two half-axles stationarily mounted on said unit and extending in opposite directions from said unit at right angles thereto, a muller having an ovoid longitudinal cross-section and mounted to rotate freely on each of said half-axles, two arms stationarily mounted on said unit and each arm being parallel to the half-axle which is located on the same side of the stationary unit as said arm, a plurality of discs, sleeves supporting the discs, said sleeves being freely mounted on each of said arms, stationary sleeveskeyed to said arms and separating' said freely-mounted sleeves from each other, elastic coupling members for securing each freely-mounted sleeve to an adjacent stationary sleeve, and means for rotating said pan.

4. Mixergrinder for foundry sand comprising in combination a frame having a central vertical shaft, at least three Wheels tted with tires and spaced at equal angular distances from each other relatively tothe central vertical shaft carried by said frame, a pan which is guided by said shaft and carried on said wheels, means .for rotating at least one of said Wheels, at least one muller freely mounted on a muller axle which is generally parallel to a radius of the pan and displaced to the rear of said radius relatively to the direction of rotation of the pan, the peripheral surface of said muller being located at a short distance from the bottom of said pan, at least one arm which is substantially parallel to said muller axle and located in front of said axle relatively to the direction of rotation of the pan, a plurality of discs, a disc-carrier rod to which each disc is rigidly fixed and which is adapted to pass through a sleeve which is freely mounted on said arm, means for adjusting the angular position of said rod with respect to said sleeve, means for adjusting the angular position of said sleeve with respect to said arm, said adjusting means comprising an elastic member which brings back said sleeve into the initial position thereof when said sleeve has been displaced therefrom, and a discharge chute which has its opening in said pan in the vicinity ofthe periphery thereof.

References Cited UNITED STATES PATENTS 12,054 12/1854 Cutler 241-117 952,820 3/ 1910 Lansdowne 241-117 3,304,588 2/1967 McIlvaine 241-110 X FOREIGN PATENTS 344,449 6/ 1904 France. 545,663 10/ 1922 France. 1,342,129 6/ 1963 France.

43 8,491 10/ 1925 Germany. 596,517 8/ 1933 Germany 278,069 9/ 1927 Great Britain. 322,185 10/ 1934 Italy.

WILLIAM W. DYER, JR., Primary Examiner. R. I. ZLOTNIK, Assistant Examiner.

Claims

1. MIXER-GRINDER FOR FOUNDRY SAND COMPRISING IN COMBINATION A CENTRAL SHAFT STATIONARILY MOUNTED ON A FRAME, A PAN OF RELATIVELY SUBSTANTIAL DEPTH WHICH IS MOUNTED TO ROTATE FREELY ON SAID SHAFT, A RADIAL UNIT STATIONARILY MOUNTED AT THE UPPER EXTREMITY OF SAID SHAFT, A FEEDHOPPER CENTRALLY CARRIED BY SAID UNIT AND PROVIDED WITH A CONDUIT WHICH HAS ITS OPENING CLOSE TO THE CENTER OF THE PAN, TWO HALF-AXLES STATIONARILY MOUNTED ON SAID UNIT AND EXTENDING IN OPPOSITE DIRECTIONS FROM SAID UNIT AT RIGHT ANGLES THERETO, A MULLER OF OVOID LONGITUDINAL CROSS-SECTION MOUNTED TO ROTATE FREELY ON EACH OF SAID HALF-AXLES, TWO ARMS STATIONARILY MOUNTED ON SAID UNIT AND EACH ARM BEING PARALLEL TO THE HALF-AXLE WHICH IS LOCATED ON THE SAME SIDE OF THE STATIONARY UNIT AS SAID ARM, DISCS MOUNTED ON EACH OF SAID ARMS IN SEPARATELY ORIENTABLE MANNER, A DISCHARGE CHUTE LOCATED AT THE PERIPHERY OF SAID PAN, A DEFLECTOR ORIENTABLY MOUNTED AT THE EXTREMITY OF THE ARM WHICH IS ADJACENT SAID DISCHARGE CHUTE, AND MEANS FOR ROTATING SAID PAN.