US1217786A - Sifter. - Google Patents

Description

M. D. LEMASTER.

SIFTER.

APPLICATION FILED FEB- l8. l9l5- Patented Feb. 27,1917.

5 SHEETS-SHEET 1.

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M.- n. LEMASTER.

SIFTER.

APPLICATION HLED FEB. 18. ms.

Patented, Feb. 27, 1917.

M. D. LEMASTER. SIFTERL.

APPLICATION man rEB. 1-B. 1915.

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Patented Feb. 27, 1917.

' M. n. LE'MASTER.

SIFTER, APPLICATION FILED FEB. 18, l9l5 Patented Feb. 27,1917

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1VIAURIGE D. LEMAS'IER, or cnamnnnseune, rEnnsYLvANia Assienon TO THE -WOLF COMPANY, or cnAMBERs'BoR's, PENNSYLVANIA, A CORPORATION on PENN- SYLVANIA.

To all whom it may concern:

Be it known that I, Mnomcn D. LEMASTER, a citizen of the United States, and a resident of Chambersburg, county of Franklin, 5, State of Pennsylvania, have invented certain Improvements in Sifters, of which the following is a specification.

My invention relates to certain improvements in the mechanism for actuating sifters or gyrators used in the process of milling, or for sieving, bolting and scalping. This type of structure is suspended so as to be free to swing.

One object of the inventionis to construct the mechanism for driving the structure so that it will be carried solely thereby and will be driven through a flexible connection, such as a belt, and will be driven from the power mechanism.

provide means for controllingthis movement.

A still further object is to prevent the rapid movement of the weighted governor. Another object is to provide means to hold the bearing in positive alinement.

In the accompanying drawings: Figure 1, is a plan view of a suspended sifter illustrating my invention; Fig. 2, is a vertical elevation with one of the sieve casings removed; the bearings being in section;

Fig. 3, is a sectional plan view aar., Fig. 2; 3 Fig. 4, is an enlarged sectional view of the dash pot;

Fig. 5, is a perspective view of the weighted governor;

Fig. 6, is a on the line detached perspective View of 0 one of the arms which carry the governor;

Fig. 7, is a perspective view of one of the tie plates for the bearings;

Fig. 8, is a sectional elevation illustrating a modification of my invention; and i Fig. 9', is a plan view of a modification illustrated in Fig. 7.

Referring in-the first instance to Figs. 1 to 5, inclusive, 1, l are the sectional casings I inclosing the sieves over which the material 5? flows in its passage through the machine.

This structure, in the-present instance, consists of four casings arranged so as to provide a quadrangular opening 2 at the center. 3, 3 are the suspending cables,'which are secured to the casing at a point about midway of its depth and are suspended from structure is also secured. The bridge trees 4 and 5 are connectedtogether by tie plates 30 so as to hold the bearings in positive alinement and to make the drive self contained. In the bearings 4 and 5 are ballv bearings 7, of any. suitable type, and extending through the bearings is a vertical shaft 8 supported by a thrust bearing 85. On the r upper end of the shaft, beyond the sieve 20 A further object of the invention is to casings, is a pulley 9 and mounted on brackets 1( secured to the upper end of the sieve structure are flanged guide wheels 10 around which passes thedrivingi belt. This belt also passes around the pulley 9 and around a driving pulley adapted to bearings hung from the ceiling, or other overhead structure; the belt being ofisufiicient length as not to interfere with the lateral movement of the structure.

Secured to the shaft are arms 11, spaced apart as shown in Fig. 2, and these arms are secured to the shaft by a key 12 and are provided with clamp heads 11 which partly encircle the shaft 8 and hold the arms rigidly in place, as there is considerable strain on these arms when the counterweight is traveling ofi' center; 7 13 is the governor, which is mounted on a pivot pin 14 carried by the arms 11 and is slotted at 15 to receive the shaft 8. 16 is an adjusting screw carried by the governor- 13 and is located so as to bear against the shaft 8, and it can be adjusted to regulate the position of the .governor'in respect to the shaft for a purpose described hereinafter.

Mounted on the pivot 14 are two springs 17, one mounted above the governor and the other below it, and one end of each spring engages the governor 13 and the other end engages the arms 11, and the tendency of the springs is to keep the governor in its normal position, viz, with the end of h adjus i g sc w In'order to regulate the movement of the Specification of Letters Patent. Patented Feb. 27, 1917.

16 against the shaft 8..

weighted governor from the shaft, I provide two dash pets 18 in the present 1nstance, which have pivot pins 19 secured thereto which are swiveled in openings in the arms 11. In each dash pot is a piston 20 having a. rod 21 which is mounted on a pivot pin 22 carried by the. governor 13. In the piston are two passages 23 and 24. The passage 23 is a small leakage passage which is open all times, and the passage 2-1- is tapered and has a ball check valve 25 therein, acid in placeby a cross bar26, so that the ball valve will close the passage when the piston is moving in the direction of the arrow, Fig. i, and will open the passage when the piston is moving in the opposite direction, so .nat, when the weighted governor is forced out in the direction of the arrow, Fig. 1, when the apparatus is et in motion it is prevented from moving rapidly by the fluid in the dash pot, as the only escape for this fluid is through the small passage 23, but, when the machine is asslnning a position of rest, the weighted governor is free to move toward the shaft, as both the passages 23 and are open. The adjusting screw 16 is used to adjust the weighted governor so that it can beset a trifle over the center to permit it to throw out when the machine is started.

When starting the machine, if it is found that the weight does not throw out, the set screw 16 must then be turned so as to shiftthe governor until the right point is reached. Carried by the governor is a stop plate 27 mounted on screws 28 and adjustably confined to the screws by nuts 29located on either side of the plate. This plate spans the slot 15 in the governor and limits the outward movement of the same. By adjusting the stop plate the throw of the machine is regulated. If a greater throw is'desired,

thenthe plate is moved farther from the shaft to increase the movement of the weight and if a less throw is desired, then the screws are adjusted so as to bring the plate nearer to the shaft.

In the drawings I have shown the governor located within the chamber 2 near the vertical center of the machine. This is the preferred position.

In some instances, the driving shaft may be located on the floor below the machine and the bearings and guide pulleys may be secured to the underside of the sieve casings, instead of the upper side, as shown in Fig. 8, and the belt pulley may also be located on the underside, but I prefer, where possible,

to drive the mechanism from overhead, as it gives a clear space under the sieve boxes and all parts of the machine are accessible to the operator.

InFigs. 8 and 9, I have. shown a machine in which the governor isdivided, one Section being located above the sieve structure and the other below. The driving mechanism, in this particular instance, is located on-the floor below the machine. In this case, 1*, 1* are two sieve boxes, which are spaced apart suiiiciently to allow for the passage of the tubular bearing i having a flange 4 on which the boxes rest and in which are located the ball bearings 7. The bridge tree 4: is firmly secured to each sieve box, as shown in Fig. 9. 8 is the shaft which extends through the tubular bearing 1 and at the upper end of the shaft is an arm 11 on which is pivoted, at 14", the'weighted governor 13 having a single spring and a dash pot 18 similar to that illustrated in Fig. 4-. Located under the bearing 41-" is the pulley 9 around which passes the driving belt, being guided over the flanged pulley 10 to the mechanism located below the machine, and, in the present instance, under the wheel 9, and on the shaft is a second arm 11 to which is pivoted, at 14", the second weighted governor 13 also having a dash pot. Each weighted governor has an adjusting screw 16, similar in design and construction to the adjusting screw 16 of the governor 13, and each governor section has a stop plate 27 for regulating its throw.

The tie plates 30 are made, in the present instance, as shown in Fig. 7, having two side members 31 and a connecting member 32. The side members extend beyond the connecting member and are bolted or otherwise secured to the bridge trees 1 and 5.

The operation is as follows:l/Vhen the stop plate 27 is adjusted to the desired position the mechanism is set in motion. At first the governor will rotate with the shaft, as it is preferably seta little over the center of gravity, but immediately it com-* mences to move out as the speed increases, and this movement is against the fluid in the dash pots, consequently, the governor will move out in vproportion to the escape of the fluid through the passages 23 and against the pressure of the springs 17. This movement will continue until the stop plate 27 comes in contact with the shaft 8 and the outward movement of the governor ceases. Since the weighted governor is considerably to one side of the center of rotation it causes the sieve boxes to have a gyrating movement on the central shaft, which rotates within the boxes, as the entire mechanism is suspended and is free to move, according to the position of the weighted governor.

lVhile I prefer to use a fluid, such as oil, in the dash pots, air or any other fluid may be used if found desirable.

In the present instance, I have shown a thrust-bearing 35, in Fig. 2, and 35", Fig. 8, both of the ball type, and, in the present instance a plate 36 is located on a shoulder of the upper bearing 4, and secured to the shaft 8 is a collar 37 and between the plate and the collar are the balls and their raceways,

so that the shaft, in both cases, is carried by a hall thrust bearing.

I claim:-

1. The combination of a sieving structure; means for suspending the same; hearings in the structure; a vertical shaft mounted in the bearings; flexiblemeans for driving the shaft; arms secured to the shaft; a

weighted governor located between the arms and pivoted thereto some distance from the center of rotation of the shaft; means for limiting the outward movement of the shaft; two coiled springs, one end of each spring being secured to the governor, the other'end of one of the springs being secured to one arm and the other being secured to the other arm; and a dash pot having a piston and a piston rod therein, one of the parts being secured to the governor and the other to one of the arms, said dash pot being arranged to regulate the movement of the governor.

2. The combination of a sieving structure; means for supporting the same; bearings mounted on the structure; a centrally located vertical shaft mounted in the bearings; an arm on the shaft; a weighted governor pivoted to the arm at one side of the shaft and extending to the opposite side thereof; a;

dash pot on the same side of the shaft as the pivot, said dash pot being pivotally mounted on the arm; a piston in the dash pot; a rod attached to the piston'and connected to the governor; and a spring surrounding the pivot, one end of the spring being attached to the governor and the other end being attached to the arm.

3. The combination of a sieving structure; means for supporting the same; bearings mounted on the structure; a centrally lo- Gopies of this patent may be obtained for cated vertical shaft mountedin the bearings;

an arm on the shaft; a weighted governor pivotally mounted on the arm on one side of the shaft and extending to the opposite side thereof; adjustable means. for limiting the outward movement of the governor; a spring encircling the pivot and attached to the governor ing a piston and apiston rod, one of the parts of the dash pot structure being 'secured to the arm and the other to the governor and located between the pivotand the shaft, the piston having a free passage therein and also having a second passage; and a valve mounted in the passage and arranged to control the outward movement of the governor.

4. The combination of a sieving structure; means for suspending the structure; hearings on the structure; a vertical shaft mounted in the bearings; arms secured to the shaft; a weighted governor pivoted to the arms at one side of the center and extending to the opposite side of the shaft, said governor being recessed to receive the shaft; an adjusting screw extending through the governor and bearing .upon the shaft, said screw regulating the position of the governor with respect to the shaft; and adjustable means carried by the governor for limiting the outward movement of the governor, said means coming in contact with the shaft when the governor is moved out to its full extent.

and to the arm; a dash pot hav In testimony whereof, I have signed my 7 name to this specification, in the presence of two subscribing witnesses. I

, MAURICE D. LEMASTER.

Witnesses:

FRANK M. DUNCAN,

E. D. SMALL.

Washington, D. G.

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