US2695523A

US2695523A - Vibrating mechanism

Info

Publication number: US2695523A
Application number: US17955A
Authority: US
Inventors: George L Oswalt
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-03-30
Filing date: 1948-03-30
Publication date: 1954-11-30
Anticipated expiration: 1971-11-30

Description

Nov. 30, 1954 G. 1 oswALT VIBRATING MEQHANISM Filed March so, 1948 United States Patent" yOlii/iceV 2,695,523 Patented Nov. 30, 19u54 2,695,523 VIBRATING MECHANISM George L. Oswalt, Forest Park, p Application March' so, 194s, serial No. 17,9'55

4 Claims. (cl. 74-61) i My invention relates to vibrating mechanism and more particularly to a mechanism for vibrating a mold body.

The vibrating mechanism of my invention may be applied in conjunction with a wide variety of materials, articles, or machines but it is particularly well adapted for use in the molding of concrete blocks, or the like, and I shall, therefore, illustrate it in that connection. i Concrete blocks are composed of cement and an aggregate `consisting primarily of cinders, or the like, the aggregate being of such size that evenwhen mixed proper proportion of water it does not ow readily into rspaces between the walls of a mold and cores which may be positioned within the mold. Consequently, it is necessary to vibrate the moldas the mix is fed into `it in order that the mold space may be completely and compactly filled. Vibrationnot only causes complete filling of the mold and compacting of the material therein but also speeds up the molding process. In a competitive industry such `as lthe building materials industry, speed is essential in the manufacturing operations. Hence,` vibrating mechanism in conjunction with molds has been employed in both `large and small operations of various kinds. For example, vibrating mechanism is employed in some of the larger concrete block manufacturing machines presently on the market which are adapted to produce six hundred 8 x 8" X 16 blocks per hour. The rate` of production in such a machine depends in part upon automatic delivery by a feeding mechanism of measured charges of the mix from a supply source to a mold, but also depends upon vibration of the mix for a predetermined period of time for each charging operation. In such machines, vibration of the mold may start as the feeding mechanism begins to reach the mold and continues while the feed mechanism is over the mold, and as it is withdrawn from the mold. When the feed mechanism is withdrawn, it carries back with it any of the mix which has not gravitated into the mold with the assistance of the vibratory action.

It is the primary object of my invention to provide an improved form of vibrating mechanish which will result in speeding up the production of concrete blocks by machinery presently in use or by new types of machines. I have found from extensive experiments witha large concrete block making machine, the regular capacity of which` is six hundred blocks per hour, or ten blocks a minute, that I can increase the rate of production, by the use of my invention, to nine hundred blocks per hour, or fteen blocks per minute. t

In addition to speeding up the rate of production of concrete blocks my invention also causes the blocks to be stronger by six per cent or more.

It is a further advantage of my invention that the manufacture thereof and installation in existing equipment will greatly increase the productive capacity of such with the cement and corporating my invention and portions of an automatic concrete block molding machine; t h

. Figure 2 is a diagrammatic showing of the positions of a pair of shafts and their eccentrics such as those illustrated at either of, the ends of the mold body of Figure 1;

Figure 3 is a diagrammatic` View similarv to that of Figure 2 but illustrating the relative positions of the shafts and eccentricsr after the larger eccentric has made a quarter revolution; Y

Figure 4 is a view similar to the View of Figure 2 but illustrating the relative positions of the shafts and eccentrics afterthe larger eccentric has made one-half of a revolution; and h Figure 5 is another diagrammatic View illustrating the relative positions of the shafts and eccentrics when the larger eccentric has made `three-quarters of a revolution. Referring now particularlyto Figure 1, which illustrates, fragmentarily, an automatic concrete block molding machine, there will be seen a supporting frame 1 for a mold 3. The frame 1 and mold 3 could, of course, be an integral structure which` could be designated inits'entirety as a mold body. However, for convenience in the manufacture of a variety of different sizes of blocks, and other structural elements, the mold 3 is shown as being separate but carried rigidly within the frame 1 between frame members` 5, 5 so4 that any vibrations produced within the frame are transmitted directly to themold 3. With such construction molds for other forms of blocks or structural elements may then be substituted for the mold 3.

lnteriorly of the mold 3 there mayA be a plurality of dividing walls, such as the wall 7, which form separate compartments 9 so that multiple units of blocks or other structural elements may be manufactured simultaneously. Cores 11 fixed in compartments 9, together with the dividing walls 7 and outer walls 13, define mold cavities 15 of restricted horizontal cross-section. The mold 3 may have for its bottom a closure plate or pallet 17 which is adapted to be raised and supported in place against the bottom of the mold by a plurality of supporting palletpusher plates 19. The frame 1 has independent supporting meanstnot shown) and the pallet pusher plates 19 may be.` resiliently or otherwise supported togetheriin` their various positions,

one of which positions is below the chain feeding mechnism, which is indicated generally by the reference numeral 21. The details of the various supporting means are not, however, required for an understanding of my invention. Above the mold 3 there is provided a guide mechanism, indicated generally by the reference numeral 23, which guides a feeding mechanism, indicated by the reference numeral 25, in its movement from a position beneath a hopper (not shown), wherein the feeding mechanism is in the dotted line position of Figure l, to the position, as shown in Figure 1, wherein the feeding mechanism has moved over the top of the mold 3 to deliver a measured charge of mix formed of cement, cinders,

h or other aggregate and water. The feeding mechanism 25 machinery without proportionate costby the addition of the improved mechanism. -j h In attaining the foregoing object and advantages I vibrate a mold body which has a bottom plate or pallet by accentuating the downward movement during vibration while feeding the mix into the top of the mold. That is open at its bottomand, consequently,.the wall 27 is supported beneath the guide.

The chain drive mechanism 21 is of the endless belt type andis indicated only fragmentarily. It is adapted to feed a series of pallets forward in correct spaced relation from a stack of pallets (not shown) behind and below the mold 3. As a pallet moves into position over the retracted pallet pusher plates 19, the pallet pusher plates are adapted to rise and lift the palletupwardly against the bottom of the mold 3. At. this time the feed mechanism 25 is in its rearward position (the dotted line position of Figure l) beneath a hopper (not shown) which is adapted to holda large quantity of the mix.` When a pallet such'as palllet 17 is firmly in place beneath the mold 3, the feed mechanism, 25 is automatically moved forward to carry with it a charge of the mix, and, as the feed mechanism 25 begins to slide over the top of the mold, the frame 1 and mold 3 are vibrated in a manner to be explained below. Vibration of the frame and mold continues as the feed mechanism 25 moves into its forward position, as shown in Figure l (all of the mix being removed for clearness been vibrated down into the cavities of the mold compartments 9 is"- carried' back s` that the top" surface of the mold is leveled. Vibration of the mold and frame may continue during retraction of the feed mechan'sr 25C When the4 feed mechaiii`sm`25has been fully retracted, aA pressing head (not shown) may descend from a position" above the guide'23` and mold 3 to press the mix firmly into the mold' cavities 15' against the resistance of the pallet 17. After such" a pressing head has descended a pred'eter'iniiie'dV amount' iiil order to compress the inixaiidforrrl a'block of a' certain height, the pallet pusherplates 19 and the pressing head descend together in 'spaced' relation anda formed block, or blocks, descendsY from" the mold on pallet 17 until the pallet pusher plates 19 pa'ssbelow the level of the feed chain mechanism 211, whereupon the pallet is carried forward ori mechanism 21 fodischarge at the front end thereof as shown byV pallet 17', carrying blocks 29, which are shown in dotted outline. While the formed blocks are being carriedA forward on a pallet 17', another pallet is simultaneously being forwarded by the chain feed mechanism 21 and the palletrpusher plates 19 into the position beneath the mold 3. The timed movements of the pallets and their supporting mechanism may be carried out by power means and controls of a known type which do notform a portion of the invention.

The vibrating mechanismfor the frame 1 and mold 3willnow be described; The front wall 31 and rear wall 33 of frame 11 support a pair lof

rotatable shafts

35 and 37 at one side of the mold body 3 and another pair of shafts 39 and 41V at the other side of the mold b odyr3. The forward ends of' all of the shafts find a bearing in-the front wall31l and the rear ends of each of saidshafts nd a bearing in the rear wall 33 of frame 1. In addition, the forward ends of the

shafts

35 and 39 extend-through the front wall 31 aridhave secured onto their respective free ends pulley wheels 43 and 45. A drive belt 47lconnects the pulley wheel 43 with the pulley wheel 49 which is connected to the drive shaft of an electric n'iotor 51. Similarly, the pulley wheel isfdrivingly connected by the pulley 53 to the pulley wheel which is connected to the drive shaft of the electric motor 57'.

It will be readily understood that it is not necessary that each pair ofy shafts be vertically aligned in the frame 1, nor need there be a'pair of shafts at each end of frame 1*. Other locatior'isof eccentric shafts and varying numbers of shaftsmay1 be employed so longv as a sharp downward movement and agentler upward moveinentis applied to the mold.

Shaft' 35 has'a sprocket 59 secured thereto and shaft 37 hasV a smaller sprocket 61 secured to it. The two sprockets' are drivingly interconnected by a chain 63 and the sprockets are of such relative size that the upper shaft 37 is'rotated at twice the speed of the lower shaft 35; Similarly shaft 39 has a sprocket 65' secured to it and the shaft 41 has a smaller sprocket 67 secured to it and the two sprockets are interconnected by a chain 69. Because of the respective sizes and numbers of teeth of the sprockets andV 67, shaft 41 will be driven at a speed twice that of the shaft 39. Similarly shaft 37 will be driven at twice the speed of shaft 35.

Shaft 35 has a pair of eccentric weights 71 secured to it which weights have their centers of gravity on a line'parallel to shaft 35. The upper shaft 37 also carries a pair of eccentric weights 73 the centers of gravity of which lie on'a line parallel to the shaft 37. Shaft 39- has a pair of eccentric weights 75 secured to it with their centers of gravity on a line parallel to said shaft and, similarly, the upper shaft 41 has a pair of eccentric weights 77 which have their centers of gravity on a line parallel to the shaft 41. Weights 71 are heavier than the weights 73 and the weights 75 are heavier than the Weights 77, with the

weights

71 and 75 preferably being the same size and shape and with the weights 73 and 77 preferably being the same size and shape. Although the centers of gravity of each pair of weightspreferably will be on a line parallel to the axis ofl rotation of their shaft, other suitable locations may be employed.

. It will be observed that with the shafts in the positions shown in Figures l and 2 the eccentric Weights of each-shaft extend vertically upwardly. After one complete revolution of

shafts

35 and 39 all of the eccentric weights will again assume the position shown in Figure l, the 'uppershafts 37'and41`a'nd their respective'eccentrics having in the meantime made two complete revolutions before returning to the position shown in Figure l. It will be appreciated that the eccentric weights may take other forms and that'in fact they may be intlgrfal portions of the various shafts or offsets of said s a ts.

When the four shafts are driven, the fact that the centers of gravity of said shafts, plus their respective eccentric weights, lie toone side of the central axes of the respective shafts will cause reactions in the supporting means for the shafts. As`the center of gravity of each shaft and its weights move upwardly the supporting means is pushed downwardly and vice versa. It will be readily seen, therefore, that wherithe four shafts are` rotating, the frame 1, which constitutes' the`supporting means for the variousshafts, will bevib'r'ate'd. If the eccentrics of all of the shafts followedthe 'samepath at the same speed and`were coordinated in their positions, their reactions against the frame 1 wfouldallbe directed inthe sarnedirectionat the saine tiriel However, the upper shafts'v 37' andy 41, having thesmaller pairs of eccentric weights 73' and 77,respeet'ivelyrtate twiceas' fast as thelowei` shafts'35 and 39,' having the pairs of eccentrics 71 andY 75, respectively.- Consequen'tly, duringthe rotationof a pair of shaftsat' either end `of the fratrie'` 1 the large pair of .weights andthe small pair of weights will be alternately cooperatingto provide acumulative reaction on the frarnel and'rnold 3, or will beoppsing. eachother andi/vill be applying a reaction resulting from the"diiferencebetweenthetwo forces. lngthe preferred forni of rrfiyV invention the action of the'p'air of shafts 35 andY 37 is the same as the action of the pair of shafts'39 andlyexc'ept that the two pairs are rotating inpopposite directions. The purpose of havingthem rotate'in oppositedireetionsl is to prevent` reactions inI asideward direction since that would tend to cause themold bodyand frame torriove sidewardly.4 SinceY the correspondingy shafts aty opposite sides ofthe mold 3j arev rotating at-the same speed and the various eccentrics of said shafts follow correspond` ing paths and have similarv speeds, thev reactions in a sidewise direction cancel each other and the vibration ofthe mold isltherefo're substantially only in an upward and downward'direction. l

If reference will now be made to Figures 2, 3, 4 and 5 wherein

shafts

35 and 37 are illustrated` diagrammatically' along with their respective eccentrics 71Y and '73, it will be possible to understand betterY the effect which the rotating shafts and eccentricshave with respect to each other.- The action about; to be-,described will be the same for the pair ofshafts 39 and 41:- When the shafts' 35'and 37 are in the position shown in Figures l and 2V and arein motion; the reactiona'gainst the frame 1 and mold 3 will be in a downward direction. Then as the shafts 'rotate clockwise it will be seen that when shaft 35 has made a-` one-quarter revolution the upper shaft 37 has made a one-half revolution. Since the reaction against the supporting frame 1 is in the opposite direction from the moving center of gravity of each eccentric, it will be seen that, when the

shafts

35 and 37 have reached the position shown inFigure 3, the vertical componentof reactive force of= thev upper shaft 37 and its eccentrics is now in' 4an upward direction whereas the verticalcomponent of the reactive` force exerted by the eccentrics 71 of shaft 35 is zero. Consequently,`the frame isbeing moved in a direction opposite to that in which it was being-moved' when the shafts and eccentrics were in the position shown in Figures l and 2. When the

shafts

35 and 37 are moving and are intermediate the positions shown in Figures 2 and 3, shaft 37 and its eccentrics 73 willbe lmovingfrorri a position wherein they exert a downwardreactive force to a positionwhereinthey exert ,anupward' force, while the shaft 35 and its eccentrics 71 move from aposition wherein they are exerting'a downward reactiveforce to aposition wherein they exert no vertical force in either direction.

As

shafts

35 and 37 rotate farther and shaft'35-rea'ches a position whereinit has completed Onrh'alf of' a revolution, the shaft 37'and its eccentric'73V will have madeV one complete revolution. Such positions are shown in Figure 4 Eand the reactions'produced by :the

eccentrics

73 and 71 will be directly opposed to each other. Since shaft 3S carries a heavier pair of eccentrics than does shaft 37, the upward reaction will exceed the downward reaction so that the differece in forces will still produce upward movement of th.: frame 1 and mold 3.

When the shaft 35 and its eccentrics 71 have made three fourths of a revolution, the shaft 37 and its eccentrics 73 will have made one and one-half revolutions and the reaction produced by shaft 37 and its eccentrics will be upward while the reaction produced by the shaft 35 and its eccentrics 71 in a vertical direction will be zero. Then as shaft 35 makes another quarter turn from the position shown in Figure 5 so that it attains a position such as that shown in Figure 2, the shaft 37 and its smaller pair of eccentrics 73 will rotate from the position shown in Figure 5 to a position 180 there from and will attain the position shown in Figure 2. At that time both

shafts

35 and 37 and their eccentrics will produce a cumulative reaction on the frame 1 and mold 3 in a downward direction.

From the foregoing it will be seen that the upward movement, produced by the rotation of the pairs` of shafts and their eccentrics at opposite ends of the frame 1, will be a series of more gentle or moderated movements than will the series of movements of the frame and mold downwardly, since the shafts and eccentrics cooperate to produce a sharp downward movement, but are working directly against each other during at least a portion of the time when the frame 1 and mold 3 are directed upwardly. When the

shafts

35 and 37 rotate from the position shown in Figure 5 to that shown in Figure 2, more and more force will be exerted by the rotating shafts and their eccentrics in producing a downward movement and the downward movement will be accelerated as the reactions of the two shafts and their weights against the frame become increasingly cumulative.

It is preferable to have the positions and movements of the pairs of shafts and their eccentrics at each end of the frame 1 coordinated so that the reactions are identical at each end of the frame, or substantially so, and to attain that end the mechanisms illustrated in my copending application, Serial No. 11,482, tiled February 27, 1948, may be employed.

As an example of one form of coordinated mechanism, reference may be had to the mechanism which is shown in dotted outline and is identified by the letter A. The mechanism A comprises a pair of sprockets 81 and 83 v/hich intermesh, said sprockets being carried on shafts 85 and 87, respectively, which are borne in the front wall 31 of the frame 1. Alongside the sprockets 81 and 83 on the respective shafts 85 and 87 are smaller sprockets 89 and 91, sprocket 89 being connected by chain 93 to a sprocket 95 on the shaft 35. The sprocket 91 is connected with a sprocket 97 on shaft 39 by a chain 99.

It will be seen that when the motors 51 and 57 are started they will drive the

shafts

35 and 39, respectively, through the pulley Wheels connected with the motors and with said

shafts

35 and 39. The

sprockets

95 and 97 on

shafts

35 and 39, respectively, will drive the shafts 85 and 87 through the respective chain and sprocket drives so that the

larger sprockets

85 and 83, respectively, will rotate in opposite directions and'mesh with each other. If one motor lags behind the other it will be assisted by the other motor through the positive interconnection just described. Since the positions and movements of the corresponding eccentrics on the pairs of shafts at opposite sides of the mold 3 are coordinated, the frame 1 and the mold 3 will rise and fall uniformly along their length instead of having one end up while the other end is down. As a result the substantially uniform vibration along the full length of the frame 1 and mold 3 provides blocks of uniform density, size and strength.

At the same time the driving of

shafts

35 and 39 will cause the driving of the upper shafts 37 and 41, respectively, by means of the chain drives between the

shafts

35 and 37 and between the shafts 39 and 41, respec tively. Rotation, in the manner specified, of all of the shafts and the eccentrics connected therewithwill then produce the desired vibratory action, namely, uniform vibration throughout the length of the frame 1 and mold 3, which vibratory movement will have sharp downward movements and gentler or moderated upward movements. It will be appreciated that with the coordi nating mechanism A one motor of suitable size could be employed in place of the two motors 51 and 57.

Ordinarily the motor, or motors, will be started when the feeding mechanism 25 has moved forwardly in the guide 23 from the dotted line position to a position wherein the forward end of the feeding mechanism begins to pass over the mold 3. Vibration continues While the feeding mechanism moves forward into the position shown in Figure l and continues while the feeding mechanism remains motionless and also as the feeding mechanism is withdrawn from above the mold 3. Controls for starting the motors and stopping them in proper sequence may be employed so that the operation of the vibrating mechanism may be automatic.

While I have illustrated a preferred embodiment of my invention I do not intend to be limited thereto, since, to my knowledge, I am the rst to conceive of vibrating mechanism wherein the downward movement is accentuated and the upward movement of the vibrated mold or frame is moderated.

I claim:

l. In combination, a frame structure adapted to hold material and to be vibrated, shaft supporting means at opposite ends of said frame structure, a pair of rotatable shafts rigidly carried at each of said ends of the frame structure in said shaft supporting means, eccentrics carried by all of said shafts, the eccentric of one shaft of each pair being of lesser weight than the eccentric of the other shaft, said shafts of each pair being drivingly connected whereby` the shaft having the smaller eccentric weight is driven at twice the speed of the other shaft, but in the same direction, and whereby the eccentrics of each pair of shafts periodically both reach the uppermost position in their paths of rotation at the same time and periodically the shaft having the eccentric of lesser weight reaches the uppermost position of its path of rotation when the shaft having the eccentric of greater weight reaches the lowermost position of its path of rotation, means for driving the shafts at one end of the frame structure in one direction, and means for driving the shafts at the other endof the frame structure in the opposite direction.

2. The combination of claim 1 together with means for drivingly interconnecting the respective drive means for said pairs of shafts.

3. In combination, a frame structure adapted to support material and to be vibrated, a pair of rotatable elements rigidly and rotatably supported by said frame at each of the opposite ends thereof, each rotatable element having its center of gravity lying to one side of its axis of revolution, one rotatable element of each pair having such weight and such position of its center of gravity that the reaction produced by its rotation is less than that produced by the other rotatable element of the pair, said elements of each pair being adapted to be driven at different angular velocities and in the same direction whereby their eccentricities periodically produce cumulative reactions against the frame in one vertical direction and then opposing reactions against the frame in the opposite vertical direction, means for driving the pairs of rotatable elements at opposite ends of the frame coordinately and in opposite directions so that the cumulative reactions and the opposing reactions at each end of the frame are the same to cause rise and fall of the frame uniformly along its length.

4. The combination of claim 3 wherein the rotatable elements of each pair are drivingly interconnected so that their centers of gravity periodically both reach an extreme vertical position in their paths of rotation at the same time and periodically the center of gravity of one of said rotatable elements reaches the uppermost position of its path of rotation when the center of gravity of the other reaches the lowermost position of its path of rotation.

References Cited in the tile of this patent UNITED STATES PATENTS Number Name Date 1,280,269 Miller Oct. l, 1918 2,054,253 I-Iorsch Sept. l5, 1936 2,161,822 Kogl June 13, 1939 2,319,313 Flam May 18, 1943 2,353,492 t OConnor July 11, 1944 2,407,168 Lindkvist Sept. 3, 1946