US2378499A - Means of attachment for screen leaf springs - Google Patents

Description

J. L. RAPP June 19, 1945.

vMEANS oF ATTACHMENT FOR SCREEN LEAF SPRINGS ls sheets-sheet 1 Filed March 15. 1945' J. L. RAPP v June'19, 1945.

MEANS OF ATTACHMENT 'FO SCREEN LEAF SPRINGS 3. Sheets-Sheet 2 Filed March 15, 1943 June 19, 1945.. J. l.. RAPP 2,378,499

MEANS 0F ATTACHMENTlFOR SCREEN LEAF'SPRINGS l Filed March l5, 1943 3 Sheets-Sheet 3 Patented June 19, 1945 MEAN OF ATTACHNIENT FOR SCREEN LEAF SPRINGS John L. Rapp,

Milwaukee, Wis., assigner to Nordberg Manufacturing Company, Milwaukee, Wis., a corporation of VllisconsinA f Application March 15, 1943, Serial No. 479,169 (cl. 20a-415) 14 Claims.

My invention relates tov an improvement in vibrated screens and has for one object to provide improved vibratable supports for the vibrated screen deck. One object of the invention is to provide improved means for securing spring leaves, for such a screen, to the deck and to the screen base respectively.

Another object is to provide such securing meansfor the-spring leaves as willprevent the necessity vof perforating or otherwise weakening the spring leaves. Another object is to provide means for readily removing individual spring leaves or groups of spring leaves without dismantling the screen as a whole. f

Otherobjects will appear from time to time throughout the specication and claims.

My invention is illustrated more or less diagrammatically in the accompanying drawings, wherein:

Figure 1 is a side elevation with parts broken away and parts in longitudinal section;

Figure 2 is an enlarged transverse section with parts omitted taken on the line 2 2 of Figure 1;r

`Figure 3 is a section ywith parts broken away taken on the line 3-3 of Figure 2;

Figure 4 is a section along the line 4--4 of Fig. 3;

Figure 5 is a section on an enlarged scale takenr along the line 5--5 of Figure 4;

rFigure is a vertical section through the end of the screen illustrating the application of similar securing means to another portion of the screen.

Figure '7 is a section, on anenlarged scale, through one of the boxes or sockets shown in Fig. 6, and Figure 8 is a section on' the line 8-8 of Fig. '7.r I

Referring to the drawings, I generally'indicates any suitable support or loor surface upon which the screen' structure asa whole may be mounted. 2 generally indicatesabasewhich may include a plurality of longitudinally extending side members 3 and transversely extending cross members 4. f y

While my spring supports may be applied to a plurality of screens of different types, I illustrate the invention herein as employed in a balanced screen, in which the screen deck, generally indicated as A, vibrates in opposition to a weight structure generally indicated as B, both. supported on the base 2, by means of the below described `supporting springleaves. The weight structure B may include a pair of longitudinally` extending weight bars 5 which may be secured together as by the end structure 6, carrying the feed box l, and vibrates as a unit. Any suitable means not herein described in detail, may be employedA for moving the weight structure and the deck at a rapid speed in opposite directions I illustrate for example, any suitable motor l0 mounted on the base 2 and provided with a drive pulley Il;

about which passes a belt i2, which," in turn, passes about a driven pulley I3, which drives any suitable rotor structure Illa, having an eccentric element. It rotates in a housing I4. Any suitable eye passes about the eccentric and issecured to the opposite of the two vibrated members. Thus in response to rotation of the motor, the eiective distance between the two vibrated members A andB is varied at a rate depending' upon the rate of rotation of the rotor Ma.

Referring to the invention, I illustrate a plurality of socket members l1 located on the base. Each vsuch socket member has a corresponding socket member on either the weight structure B or the screen deck A.v The sockets may be welded in place, or otherwise secured Referring i'lrst to the sockets on the base 2, each such socket is in effect a box having a closed bottom plate I5, an endwall IB perpendicular to the bottom plate I5,v side ,walls Il, perpendicular to the bottom plate I5, andan end wall I8 having an inclined face I9. The

bottom plate I5 is also provided with an aperture 20 which, when the device is in use, is norwedge 25 may be screw threaded as at 2l to receive an actuating screw VV28, the head 29 of which abuts against' the. plate 22 kand may bel provided with any suitable spring or lock washer 3D. It will be understood that in response toi rotation of the screw 28 in the appropriate direction, the wedge 25 is drawn toward the bottom plate '|5. The result is to lock the lower ends of the springs, and the appropriate spacers, rm-

1y in position in the socket.

The upper ends'of the springs, with corresponding 'spacers are mounted in similar sockets which are secured to the screen deck A or the 'weights B, as the case may be. These upperl sockets are identical with the lower sockets except that'their are inverted, and do not call for further description.

In the use of the device, it will be understood that a group of spring leaves is inserted into each of the sockets along the base 2. These spring leaves, with their appropriate spacers, are then tightened in position by actuation of the Wedge of each socket. Tightening of the wedge also serves to hold the plate 22 in position to close the bottom aperture 20. The screen deck, or the weight structure as the oase may be, is then posi-'- tioned on the upper ends of the sprin-gs and the upper spring ends, with their appropriate spacers' 24 are locked in the sockets by the wedges 25 of the upper sockets. l

It will be understood that once the screen has been completed and is ready for use, or has been used, any particular spring leaf unit, can be quickly and easily disassembled for new leaves.

It happens that leaves sometimes break in use. L

Where one or more of a group of leaves does break, a leaf or group of leaves can be readily removed from and replaced in the screen with'- out disassembling the screen as a whole, All that is necessary is to release the wedges 25 at the upper and lower ends of the particular spring leaf group which is to be removed. As a matter of convenience, the plate 22I of the upper socket may, for example, be entirely removed or swung out of alignment with the aperture 2li. Then the leaf or leaves can be drawn out through the aperture and replaced. This makes it unnecessary to release more than the particular set of spring leaves which are being checked or re moved. The opening in the plate to accommodate the bolt 28 may be enlarged or elongated to ac'- commodate the lateral movement of the wedge as it is drawn up, instead of allowing the clearance shown between the projection 2| and the aper-A ture 20.

A further advantage is the avoidance of the necessity of aperturing spring leaves to pass securing bolts therethrough, as has been the past custom in using spring leaves of this type, Avoiding the use of drilled openings in the leaves of hardened steel, reduces the cost of spring leaves. Further, the avoidance of the drilled openings eliminates or considerably reduces spring leaf breakage. It is well known that stresses tend to concentrate about any opening. The piercing of the ends of the spring leaves very substantially reduces the strength of the leaves and provides a center of strain where the leaf tends to give way.

The present invention diminishes the work andv expense of initially assembling the springs and vastly increases the ease, speed and economy of servicing the screen when weakening or breakage of the spring leaves takes place. As above pointed out, the tendency of the spring leaves to break is radically reduced. 1

In the structure in which leaf vsprings are bolted to the screen deck or base by passing bolts through openings in the leaves of the spring, the steel must be drilled prior to tempering it. Heat treatment distorts steel and gives rmisalignment of the holes. In assembling the springs, it has been found that the last bolt in the assembly usually fits extremely tightly because of misalignment of the holes and makes itnecessary to drive the. last bolt in place. It thereby sets up an initial strain in the leaf springs which contributes greatly to their failure. This is avoided in the present structure. k

It will be understood that the spacers are held in place only by the friction exerted by the wedge 25 and can readily be inserted or removed when the wedge is released. It will also be understood that the sockets may take spring leaves of varying thickness and in varying numbers by the use of any suitable shims or spacers of varying thickness andnurnber.l

Referring to Figures 6 to 8, I illustrate the invention as applied to the springs connecting the sidebar weight structure and the deck. Referring to Fig. 6, the deck is generally indicated as A1 and the side bar structure as B1. lt will be understoodthat Mb generally indicates a housing for the vibrating or eccentric mechanism, the details of which do not form part of the present information. This housing is connected to the deck structure A1 by the springs below described. In the housing rotates any suitable rotor or eccentric not herein shown and not of itself forming a part of the present invention. It will be understood that an appropriate connection between Vsuch rotor and the weight vstructure B1 is provided,I so that in response to the rotation of the rotor, the weight structure B1 and the deck 1 structure A1 are vibrated in opposition to each other. The housing Mb and the opposed end of the deck A1 are provided with opposed sockets or boxes shown in detail in Figure '7, and of somewhat stronger or heavier construction than the corresponding boxes or sockets I1. Each such box includes a rear or bottom wall 5l), a side wall 5| perpendicular thereto, other side walls 52 per- ;pendicular both to 50 and to 5| and a slightly inclined side wall 53, adapted to engage the inclined face of the wedge 54. Thus, a live-sided box is provided, into the open end of which is inserted a plurality of spring leaves and spacers 55a. These leaves are herein shown as having thicker spacers 56 at each side of the spring group. The bottom 50 has an aperture 51 of sufficient width to permit individual spring leaves and spacers to be withdrawn therethrough if necessary.` The wedge 54 has a face 58 which is perpendicular to the bottrn 50. Its opposed inclined face 59 con forms to the inner face of the inclined Wall 53. The wedge may be provided lwith an aperture 60 `extending entirely therethrough. The wedge may be drawn into position by a bolt 6| having head 62 engaging the lar-ge end of the wedge. Preferably the diameter of the belt is somewhat less than vthe diameter of the aperture 6D. 63 is a closure plate having a lug 63a penetrating the aperture 51. The bottom 5D and the closure plate 63 `are penetrated by apertures 64 and 65 respectively, which are both of greater diameter than the bolt 6|. 66 is any suitable lock washer or Washer, and 61 is a nut for drawing up the bolt 5|. It will be understood that the groups of spring leaves 55 may lieemployed in @pairs at each end of the housing Mb s'o that four sets may constitute a complete connection between the deck structure A1 and the housing |4b.

It' will be realized that while I have shown and described an operative device, still many changes in size, shape, arrangement number and disposition of parts might be made without departing materially from the spirit of my invention. I wish, therefore, that my 4showing be taken as in a broad sense diagrammatic.

The use and operation of the invention are as follows:

I illustrate an improvement lin securing means for the ends of leaf springs or groups of leaf springs, which is particularly applicable to, but not groups of spring leaves 23 which t at theirends into boxes or sockets on the base structure andv on the weight structure and the deckstructure respectively. While my inventiony may be'applied to a wide variety of screens, the particular type herein shown is vibrated by 'a rotor actuated by a motor yIt'l on the base. 13 is a driven y pulley for rotating the'rotor. The rotor maybe rotatedly mounted in any vsuitable housing Ma.

The details of the rotor do not form part of the present invention, but it Will be understood that the housing Ma is flexibly secured to the deck' structure A as by the spring leaves 55 of Fig. 6,'

and that the rotor includes an eccentric connection with' the Weight structure B. Thus in response to rotation of the rotor both the weight structure and the deck structure are vibrated but in opposite directions.

An important advantage of my invention` is the prevention of breakage resulting from the avoidance of any necessity of drilling holes through the spring leaves. The steel must be drilled prior to tempering it, and heat treatment distorts the steel and misaligns the holes. Therefore, the avoidance of any necessity of drilling holes through the spring leaves materially adds to the life and strength of the leaves.

In the spring leaves .55, the tendency to slip because of the forces exerted lengthwise of the spring maybe substantial. To counteract this I employ a substantially stronger box around the spring leaves, and in practice, somewhat decrease the angle of the wedge to. increase the clamping action. It must bek remembered that the forces tendingto shift the leaf springs laterally are very large and that in bending the groups o-f springs the outer leaf of the convex side of the defracted group will be too short to accommodate the length of the inner leaf on the concave side. Thus. the forces tending to cause slippage become very large. However, I find that the structure herein shown is adequate firmly to hold the spring leaves. I have shown, in connection with Fig. 6 and the leaves 55, the use of a through-going bolt BI.

rIhis has an advantage, in that in tightening a nutwith ya wrench there is a tendency to slip the nut laterally, as -but rarely does a nut lie flat against the washer or an abutting surface. This,

in turn, may tend to bend the structure and tend to break the stud orl bolt in junction with the wedge. The through-going bolt structure of Fig. 6 eliminates this weakness, and it will be understood that, if desired, this type of bolt may be employed also with the sockets or boxes i1 on lthe base and on the weight structure and deck structure. I claim: l. In spring supporting means for a vbrated screen deck, a base element, a plurality of up-v wardly open sockets therein, having side and end walls, a deck having a plurality of downwardly open sockets,v having side and end walls, one or more flat spring leaves for each opposed pair of sockets, the upper ends of whichk extend into a socket on the deck, the lower ends ends normally extend, each having an aperture of suincient size to permit the insertion or Withdrawal of a leaf therethrough. v

2. In a supporting spring assembly for vibrated members, a supporting member, a vibratable member, opposed sockets on the two members, one

or more iiat spring leaves the opposite ends of which-extend kinto said sockets, each said socket having a Wall, the face of which is generally parof whichk extend into a corresponding socket on the base, and clamping means associatedV with such Sockets for clamping said leaf ends in re lation to the sockets, the end walls of the sockets, opposite the socket opening into which the leaf alle'l with the side faces of said leaves, and an opposite wall having an inclined face, a Wedge element in said socket, having a face opposed to and parallel with said parallel faced wall, and an inclined face opposed to the inclined face of said inclined faced wall, the spring ends being `located' between said opposed parallel faces, and

means for moving the Wedge element along the inclined face, and for thereby clamping the leaf ends in relation to thev socket, the socket having a wall, opposite its opening into which the leaf ends normally extend, having an aperture adapted for the passage therethrough of said leaf or leaves,

3. In a supporting spring assembly for vibrated members, a supporting member, a vibratable member, opposed sockets on the two Vmembers, one or more fiat 'spring leaves the opposite ends of which extend into said sockets, each said socket having a wall, the -face of which is generally parallel with the side faces of said leaves, and an opposite wall having an inclined face, a wedge element in said socket, having a face opn posed to and parallel with said parallel faced wall, and an vinclined face opposed to the in clined face of said inclined faced Wall, thel spring ends being located between said opposed parallel faces, and means for moving the wedge element along the inclined face, and for thereby clamping the leaf ends in relation to the socket, the socket having a wall, opposite its opening, into which the leaf ends normally extend, having an aperture adapted for the passage therethrouglci` of said leaf or leaves, and means for normally closing said aperture. y 4. In a supporting spring assembly for vibrated `members, a suporting member, a vibratable an inclined face opposed to the inclined face of` said inclined faced wall, the spring ends being located between said opposed parallelfaces, and means for moving the wedge element along the inclined face, and for thereby clamping-the leaf ends-in relation to the socket, the socket having a Wall, opposite its opening, having an aperture adapted for the passage therethrough of said leaf `or leaves, and means `for normally closing said aperture, including a plate having an extension penetrating said aperture, and an actuating. screw for said wedge element penetrating said plate.v

5. In combination, a set of flat spring leaves and means for securing the ends thereof, including a pair of opposed boxes, each having a bottom wall and sidewalls extending therefrom, said leaf springs being at their ends inserted in said boxes, at least one wall of said boxes being parallel with the flat faces of the spring leaves, and wedge means in each said box, adapted to clamp said spring leaves against said parallel Wall,

said bottom wall having an aperature therein of suincient size to permit the spring leaves to be Withdrawn therethrough, and means for normally closing said aperture.

6. In combination, a set of flat spring leaves and means for securing the ends thereof, including a pair of opposed boxes, each having a bottom wall and sidewalls extending therefrom, said leaf springs being at their ends inserted in said boxes, at least one wall of said boxes being parallel with the flat faces of the spring leaves, and wedge means in each said box, adapted to clamp said spring leaves against said parallel wall, said bottom wall having an aperture therein of a. sufficient size to permit the spring leaves to be withdrawn therethrough and a cover plate therefor, having a portion closing said aperture.

'7. In combination, a set of spring leaves and means for securing the ends thereof, including a pair of opposed boxes, each having a -bottom wall and sidewalls extending therefrom, said leaf springs being at their ends inserted in said boxes, at least one wall of each of said boxes being parallel with the fiat faces of the spring leaves, and wedge means in each said box, adapted to clamp said spring leaves against said parallel wall, including a wedge in each box, having a face paralllel to said -parallel wall, opposed to said leaf springs, and an opposite inclined face opposed to the wall of the box opposite to said parallel wall, said opposite wall having an inclined face opposed to the inclined face of the wedge, and means for imparting movement to said Wedge, incuding a bolt passing longitudinally through the wedge and having an Vabutment opposed to the large end thereof, said bolt passing through the bottom wall of the box, and an exterior actuating nut therefor, said bottom wall having an aperture therein of suiiicient size to permit the spring leaves to be withdrawn therethrough, and a cover plate therefor, having a portion closing said aperture, the bolt passing through said cover plate, the nut being adapted to exert a thrust thereagainst.

8. In a spring supporting unit for vibrated members, a base element,.an upwardly open socket on said base element, a vibrated element, a downwardly open socket onsaid vibrazted element, one or more generally flat spring leaves, the opposite ends of said leaves extending into said opposite sockets, one of said sockets having an aperture in the wall opposite to the socket opening into which the leaf ends normally extend, of a size and shape adapted to permit the insertion of a leaf therethrough, and means for normally closing said aperture and for preventing the escape of a leaf therethrough.

9. In ak spring supporting unit for vibrated members, a base element, an upwardly open socket n said base element, a vibrated element, a downwardly open socket on said vibrated element, one or more generally ilat spring leaves, the.op posite ends of said leaves extending into said opposite sockets, one of said sockets having an apern ture in the wall opposite to the socket opening into which the leaf ends normally extend,l of a size and shape adapted to permit the insertion of a leaf therethrough, wedge means positioned in said socket and means for moving it longitudinally along said spring leaves toward the wall of said socket in which said aperture is located.

10. In a spring supporting unit for vibrated members, a base element, an upwardly open socket on said base element. a vibrated element, a

downwardly open socket ony said vibrated element, one or more generally flat spring leaves, the opposite ends of said leaves extending into said opposite sockets, one of said sockets having an aperture in the wall opposite to the socket opening into which the leaf ends normally extend, of a size and shape adapted to permit the insertion of a leaf therethrough, wedge means in said socket, for locking said leaves, a closure element for normally closing said aperture and a locking element adapted simultaneously to urge said wedge means toward leaf securing position and to urge said closure toward closing position.

11. In spring securing means for a vibrated screen deck, a. socket including side walls surrounding a spring end receiving space and having an open end adapted to permit the insertion of a spring ends, and a closed end, said closed end having an aperture therein of a size and shape adapted to permit the insertion or removal therethrough of a spring leaf, one of the ,side walls having a wedge surface inclined to the surface of the opposite side wall, a wedge adapted to be inserted between said wedge surface and the spring ends, and means for urging said wedge toward the closed end of the socket and for thereby locking the spring ends in said socket.

12. In spring securing means for a vibrated screen deck, a socket including side walls surrounding a spring end receiving space and having an open end adapted to permit the insertion of spring ends, and a closed end, said closed end having an aperture therein of a size and shape adapted to ypermit the insertion or removal therethrough of a spring leaf, one of the side walls having a wedge surface inclined to the surface of the opposite side Wall, a wedge adapted to be inserted between said wedge surface and the spring ends, means for .urging said wedge toward the closed end of the socket and for thereby locking the spring ends in said socket, and means for nor- Inally closing the aperture in the end wall of the socket.

13. In spring supporting means for a, vibrated screen deck, a base element and a deck, one of said elements having thereon a plurality of sockets, each of said sockets having side walls and an end wall, one or more flat spring leaves, the ends of which extend into each said socket, and clamping means associated with said sockets for clamping the leaf ends in relation to the sockets, the end walls of the sockets opposite the opening into which the leaf ends normally extend, each having an aperture of sufficient size to permit the insertion or withdrawal of a leaf therethrough.

14. In spring supporting means for a vibrated screen deck, a base element and a deck, one of said elements having thereon a plurality of sockets, each said socket having side walls and an end wall, one or more flat spring leaves, the ends of which extend into each said socket, clamping means associated with said sockets for clamping the leaf ends in relation to the sockets, the end walls of the sockets opposite the opening into which the leaf ends normally extend, each having an aperture of sufficient size to permit the insertion or withdrawal of a leaf therethrough, a tapered clamping means including a clamp member insertible in said socket, and means for withdrawing said clamp member toward the closed end of the socket.

JOHN L. RAPP.

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