US2589115A

US2589115A - Machine for making concrete blocks

Info

Publication number: US2589115A
Application number: US63812A
Authority: US
Inventors: Russell B Nelson; Davies Miles; Neth Fred
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-12-06
Filing date: 1948-12-06
Publication date: 1952-03-11
Anticipated expiration: 1969-03-11

Description

March 11, 1952 R. B. NELSON ET AL 2,589,115

MACHINE FOR MAKING CONCRETE BLOCKS Filed Dec. 6, 1948 6 Sheets-Sheet l INVENTORS' PusseZZ B.NeZson 'Mi Zes Da 9 Fred Ne ih Fig. l. 5

March 11, 1952 R. B. NELSON ET AL 2,589,115

MACHINE FOR MAKING CONCRETE BLOCKS Filed D80. 6, 1948 6 Sheets-Sheet 2 5Q I /2 5 J7 W i 5 H E i L 1 /4 3 INVENTORS Russell E. Nelson M-[ has Davies Fred Ne'l'h.

March 11, 1952 R. B NELSON ET AL 2,589,115

MACHINE FOR MAKING CONCRETE BLOCKS Filed Dec. 6, 1948 6 Sheets-Sheet 3 Fig. 3. 4-. Fig. 5.

Russell B.NeZson Mi Zes .Davi es Fred Nei'h.

R. B. NELSON ET AL MACHINE FOR MAKING CONCRETE BLOCKS March 11, 1952 6 Sheets-Sheet 4 Filed Dec. 6, 1948 INVENTORS Russ eZZ B. Nelson Davies Fred Nei'h. 2v

Mi Les March 11, 1952 R. B. NELSON ET AL Filed Dec. 6, 1948 .6 Sheets-Sheet 5 m V m v INVENTORS 9 RusseZZ .Nelson Miles Davies 7 Fred' Ne'UL @7 f w my March 11, 1952 RB. NELSON ET AL 2,539,115 MACHINE FOR MAKING CONCRETE BLOCKS.

6 Sheets-Sheet 6 Filed Dec. 6, 1948 Fig.1 0. 9o

69 m' n 3 E QM i Yo) g 96 INVENTORS Russe Zl .B.Ne Zson, M 1' Les D v Fred Nai'h sultant movement of the concrete the mold being indicatedby arrows;

Patented Mar. 11, 1952 MACHINE FOR MAKING CONCRETE BfAOCKS Russell B. Nelson, Beaverton, reg., and Miles Davies and Fred Neth, Vancouver, Wash., assignors to Fred Neth, doing business as Columbia Machine Works, Vancouver, Wash.

' Application December 6, 1948, Serial No. 63,812

13 Claims.

Our invention pertains to concrete block making machines, in which controlled vibration and compression are utilized to produce concrete blocks of uniform density and superior strength.

It is a principal object of our invention to provide a machine for making concrete blocks in which machine the time schedule of the various steps in the operating cycle may be controlled automatically or manually to accommodate variations in the consistency of the concrete mixture to bemolded.

A further important object of our invention is the provision of a concrete block making machine in which novel cushioning means is provided in the stripper mechanism to prevent sudden shock and consequent fracture of the molded blocks during ejection from the mold.

A further object of our invention is to provide a concrete block making machine in which complete ejection of blocks from the mold may be effected during vibration of the latter. Vibration of the mold during ejection of the blocks provides a troweling action upon the surfaces of said blocks whereby a smoother finish is obtained.

These and other objects and advantages of our invention will appear from the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a front elevation of a concrete block making machine embodying the features of our invention, the parts thereof being shown in a position attained shortly after ejection of blocks from the mold;

Fig. 2 is a fragmentary side elevation of the machine as viewed from the right in Fig. 1, the parts being shown in position ready for charging of the mold with premixed concrete material,

the movable arrangement of said parts being indicated by dotted lines;

Fig. 3 is a fragmentary side elevation of the forward end of the machine illustrated in Fig. 1, the parts thereof being shown in the position attained after pressing of the concrete material in the mold and just prior to ejection therefrom;

Fig. 4 is a fragmentary side elevation similar to Fig. 3 showing the parts of the machine in the position of complete ejection of the concrete blocks from the mold;

Fig. 5 is a fragmentary side elevation similar to Fig. 3 showing the parts of the machine in a position attained after ejection of the blocks from the mold and intermediate the positions illustrated in Figs. 4 and 1, respectively;

Fig. 6 is a fragmentary side elevation. partly in section, of the vibrator mechanism of the machine taken along the line 6-6 in Fig. 1, the direction of rotation of the cam drive and the rematerial in Fig. '7 is a fragmentary sectional view taken along the line l-l in Fig. 1 showing in detail the construction of the spring mounting for the ejector system, the magnitude of spring oscillation being indicated by vertically spaced lines identified by arrows;

Fig. 8 is an elevation of the upper section of the spring mounting shown in Fig. '7;

Fig. 9 is a fragmentary side elevation, partly in section, of the control mechanism of the machine illustrated in Fig. 1, showing the arrangement of parts for obtaining automatic or manual operation of said machine; Y

Fig. 10 is a fragmentary side elevation of a modified form of vibrator mechanism adapted for use in the machine shown in Fig. 1 in accordance with our invention; r

Fig. 11 is a foreshortened end elevation of said modification as viewed from the left in Fig. 10; and

Fig. 12 is a fragmentary plan view as viewed in the direction of arrow l2 in Fig. 11, showing details of construction of the adjustment means by which the controlled vibration of the mold may be varied in amplitude and direction.

In the concrete block making machine embodying the features of our invention, the operating parts are mounted upon a rectangular frame which includes side panels I, a top panel 2, a rear panel 3, and a front panel 4. Projecting forwardly from the lateral sides of the front panel are two pairs of base members, namely an upper pair 5 anda lower pair 6. Said base members have vertically aligned holes formed therein for receiving the tubular sleeves l slidably therein. The lower ends of said sleeves are joined together below the lower base members 6 by a horizontal toggle beam 8 which is secured to said sleeves by means of bolts 9. The toggle beam is supported at its center upon the upper end of a piston rod H] which is secured thereto. The opposite end of the piston rod is connected to a piston which is movable vertically within a double acting hydraulic stripper cylinder l l. The stripper cylinder is secured by means of bolts I2 to an H-shaped bracket 13 which projects from the front panel 4 of the frame.

The bracket I3 is formed with laterally projecting flanges M on its upper edge to provide supports for the upstanding pedestals l5 which are secured thereto. A shoulder I6 is formed about each of said pedestals intermediate the ends thereof. Removable bumpers I! each have a hollowed end I8 which slidably engages the upper end of the pedestals. A shoulder I9 is formed intermediate the ends of said bumpers. Coil springs '20 encircle the engaged portions of said pedestals and bumpers and abut at their ends against the opposing faces of said shoulders. In the relaxed position of said springs, the telescoping ends of the pedestals and bumpers are spaced apart as indicated by the vertically spaced lines and arrows in Fig. 7 and may be moved together by compressing the coil springs 20. The upper ends of the bumpers are arranged to contact the toggle beam as the latter approaches its lowermost position, as is explained more fully hereinafter.

A pallet beam 2| extends transversely between the sleeves 1 intermediate the upper and

lower base members

5 and 6, respectively, and is secured thereto by means of bolts 22. Since the toggle beam 8 and pallet beam 2| are secured firmly to the sleeves 1, the unit so formed is hereinafter referred to as the stripper assembly. A platform 23 projects forwardly and rearwardly from the center of said beam. Coil springs 24 rest at their lower ends upon said platform and support at their upper ends a pallet table 25. Bolts 26 extend axially through said springs and slidably through holes provided in the platform and table to secure said springs in place. Adjustment screws 21 are mounted upon the platform 23 for vertical adjustment and are provided with lock nuts 28 for securing said screws in any position desired. The adjustment screws are arranged to contact the pallet table 25 to prevent excessive rocking of the latter during vibration, as is explained in detail hereinafter. The pallet table is proportioned and arranged to support a pallet 29 upon which the concrete blocks 30 are carried from the machine after manufacture.

A concrete block mold 3| is held suspended above the pallet table 25 by vibrator means described hereinafter. Said mold comprises a rectangular box open at the top and bottom. The mold is of conventional construction and may be designed to accommodate the production of any type of block desired. The multiple mold illustrated in the drawings is designed for the manufacture of two hollow building blocks per cycle and is shown merely for purposes of illustration. Bars 32 are secured across the upper edge of the mold and serve as supports for the cores 33 which depend into the mold and define the inner margins of the hollow blocks.

Mounted above the top panel 2 and extending centrally thereof from front to rear is an elongated box-like housing 34 open at its top and bottom. Said housing is secured at its lower edges to a plate 35 attached to the top panel 2 and in this respect forms an integral part of the frame. The forward end of the housing overlies the mold 3| in spaced relation thereto. The forward end wall of said housing is of reduced height to permit visual inspection of the top of the old. A hopper 36 is mounted removably upon lugs projecting inwardly of the sides of the housing and serves to store the concrete mixture which is to be molded into blocks. The hopper is open at its top and bottom, the latter communicating with a carrier box 31 which, in retracted position, rests upon the plate 35. Said carrier box comprises a rectangular frame having side walls 38, a rear end wall 39, and a partial front wall 40. A gate 4| is mounted slidably upon the partial front wall for vertical movement relative thereto, thus affording adjustment of the opening provided in said front end. Enlarged vertical slots 42 are formed in the gate, as shown in dotted outline in Fig. 1 of the drawings, to permit passage of said gate over the core securing bars 32 as the carrier box is moved over the top of the mold 3|.

Extending rearwardlyfrom the upper edged the rear wall 39 of the carrier box is a horizontal plate 43 which rests slidably upon brackets 44 secured to the inner sides of the housing 34. Said plate functions to seal the bottom opening of the hopper 35 when the carrier box is drawn over the mold, thus preventing escape of concrete material from the hopper. A piston rod 45 is secured at its forward end to the rear wall 39 of the carrier box and at its opposite end to a piston which is mounted slidably in a hydraulic feed cylinder 46 secured at its rear end to the rear wall of the housing 34. Thus, fluid pressure impressed upon the piston moves the carrier box forward or rearward within the housing 34, depending upon the direction in which fluid flows in the double acting cylinder.

A pressure beam 41 overlies the forward end of the housing 34 and extends laterally across the frame above the sleeves I. The ends of said pressure beam are formed with downwardly extending tubular shields 48 which loosely encompass the upwardly extending ends of the base members 5. Projecting collars 49 extend upwardly from the ends of the pressure beam and holes are formed vertically therethrough for axial alignment with the holes extending through the sleeves 'l. Toggle rods 59 extend vertically through said aligned holes and are secured to the pressure beam by means of set screws 5| provided in the collars 49. The upper end of each toggle rod is also provided with a large washer 52 which is held firmly against the top edge of the collar 49 by means of a nut 53 threaded to the end of said rod. Said washer and nut serve to aid the set screw 5| in pulling the pressure head downwardly during compression of the concrete material in the mold 3|.

The lower ends of the toggle rods extend slidably through transversely apertured bars 54. Coil springs 55 encircle said rods below the bars 54 and are secured thereon by means of washers 56 and nuts 57. The bars 54 may slide downwardly along the lower ends of the toggle rods by compressing the springs 55, but said bars are prevented from moving upwardly along the toggle rods away from said springs. The coil springs function to prevent sudden and excessive forces from being exerted upon the concrete material being compressed in the mold 3|, as is explained in detail hereinafter. To the cylindrical ends of bars 54, the lower arms 58 of toggle joints are pivotally secured. The upper arms 59 of said toggle joints are connected pivotally at one of their ends to the lower arms 58, while the opposite ends are secured firmly to a transverse shaft 60. Said shaft is mounted for rotation in bearing flanges 6| projecting from the toggle beam 8. Also secured firmly at one end to the shaft 69 is a rocker arm 62. The opposite end of said rocker arm is pivotally secured to the outer end of a piston rod 63, the inner end of which is connected to a piston which operates slidably within the hydraulic toggle cylinder 64. The rearward end of the toggle cylinder is secured pivotally to a bracket arm which is mounted firmly upon the toggle beam 8.

Arms

59 and 62, which are joined positively through shaft 60, function as a bell crank to raise and lower the toggle rods 50 as hydraulic fluid is admitted alternately into opposite ends of the toggle cylinder 64.

Brackets 68 project forwardly and rearwardly from the lower central portion of the pressure beam 41 to provide a base upon which the pressure shoes 51 may be detachably mounted. These shoes are of conventional construction and are designed to accommodate the production of'diverse types and styles of concrete blocks. The shoes illustrated in the drawings for the purpose of describing our invention comprise a plurality of bars shaped in such manner as to surround the cores 33 and to close the spacing provided between the cores and the walls of the mold wherein is contained the concrete material to be molded.

Mechanism is provided for vibrating the mold 3| in order to distribute and compress the concrete material evenly therein and thereby produce concrete blocks of homogeneous and uniform construction. The mechanism illustrated in Figs. 1 to 6, inclusive, includes a pair of vertical vibrator rods 68 secured adjacent their upper ends to the lateral sides of the mold 3| by means of brackets 69. The portions of said rods which are engaged by the brackets are of reduced diameter and are provided with threads 70 at their upper ends. The lower ends of said reduced portions thus form shoulders against which the bottom edges of the brackets abut. A nut II is threaded upon the upper end of each reduced portion and is tightened against the upper edges of the brackets to secure the mold firmly to the rods 68.

The fulcrum sections I2 of saidrods extend above the reduced portions and are of still further reduced diameter. These sections project upwardly through bearing cases 13 which are secured firmly to the lateral sides of the housing 34. The slots 74 in said casings, through which the fulcrum sections project, are larger than the diameter of the latter and thus permit lateral movement of said fulcrum sections therein.

The interior of each bearing casing is of circular shape and receives a cylindrical sleeve [5 for rotation therein. The fulcrum section of each vibrator rod 68 also extends through holes in said sleeves, said holes bein of substantially the same diameter as said sections. The sleeves and vibrator rods may thus oscillate without imparting movement or vibration to the housing 34.

The lower end of each vibrator rod 68 is provided with threads I6 by which adjustable connection is made with the shank I1 of a bearing IS. A look nut I9 engaging the threads 16 may be tightened against shank TI to secure the vibrator rods in the position selected. The combination of adjustable nuts II and I9 affords means for varying the length of the vibrator rods whereby the upper edge of the mold 3| may be adjusted with respect to the lower level of the carrier box 31. A bushing 80 is mounted for rotation within the bearing I8 and is secured firmly in an off-center position to a driven shaft 8|. Said driven shaft is mounted transversely across the front of the machine for rotation in end bearings 82 mounted on structural members 83 which are secured to the frame adjacent the lower base members 6. Drive pulley 84 is keyed to the driven shaft and receives drive belts 85 which are reeved over a similar pulley 86 mounted upon the drive shaft 81 of the motor 88, as best shown in Fig. 2 of the drawings.

The vibrator mechanism, as embodied in the structure illustrated in Figs. 10 to 12, inclusive, represents the preferred form of our invention. In this modification, each of the vibrator rods 68 are joined at their upper ends to vertical guides 89. Said guides are mounted pivotally on brackets 90 by means of pins 9| which project outwardly from said brackets into bearing holes provided in said guides.

The brackets 90 are mounted firmly on opposite lateral sides of the mold 3| by means of bolts 92. Vertical V-shaped grooves 93 are formed in the sides of said guides to receive the complementary notched edges of the channel-shaped slide members 94 which are proportioned and arranged to move vertically over the guides 89. Adjustment bars 95 are secured pivotally at their forward ends to each slide member 94 and at their rearward ends to brackets 96 mounted upon the frame of the machine. Adjustment screws 91 are secured pivotally to the adjustment bars 95 intermediate the ends of the latter. These screws extend downwardly through flanged brackets 98 secured to the structural members 83. Adjustment nuts 99 are threaded upon said screws on opposite sides of the brackets 98 to provide convenient means for varying the vertical position of the slide members 94 upon the guides 89.

The rearward ends of brackets 90 are offset outwardly away from the sides of the mold 3|. Spaced parallel links I00 are secured pivotally at one of their ends to said brackets and at their rearward ends to triangular plates It. A second pair of spaced parallel links I02 are secured pivotally at one of their ends to said triangular plate IOI at right angles to the connections of links I00. The lower ends of links I02 are secured pivotally to brackets I03 mounted upon the structural member 83. The arrangement of parallel links I00 and I02, respectively, functions to prevent rotation of the mold 3| about a horizontal axis, as is explained more fully hereinafter. The lower ends of the vibrator rod 68 are joined to the driven shaft through the eccentric cams as discussed hereinbefore in the description of the structure illustrated in Figs. 1 to 6, inclusive.

The operation of the electric vibrator motor 88 is controlled in either of the above discussed modifications by means of a magnetic switch (not shown) which is energized by toggle switch I04 located upon the inner wall of the housing 34. Said toggle switch is closedby a contact arm I05 mounted upon the plate 43 when the carrier box 31 moves forwardly over the mold. The switch I04 may be arranged at any point along the path of travel of the arm I05, it being preferred-to arrange the switch at the point where said arm makes contact when the carrier box is superimposed over the mold. In this manner, vibration of the mold does not occur until the carrier box and the concrete material contained therein are disposed above the mold. The magnetic switch is de-energized by a second switch I06 which is secured to one of the upper base members 5 and depends downwardly for contact with the pallet beam 2| when the latter is in its uppermost position. In this position, the switch I06 completes the circuit through the magnetic switch and motor 88. However, when the pallet beam moves downwardly during the ejection of blocks 30 from the mold, switch I06 breaks said circuit and stops the vibrator motor 88, as is explained more fully hereinafter.

Mechanism is provided by which the sequential operation of the block making machine may be performed manually or automatically. Except for the operation of the vibrator motor 88, the remaining elements of the machine are operated preferably by means of three hydraulically actuated piston-and-cylinder units, namely the feed cylinder 46, the stripper cylinder I I and the toggle cylinder 64. Each of these cylinder units is double acting, that is, fluid pressure is admitted alternately to opposite sides of the piston to move the latter in opposite directions within the cylinder. A control box IGI is mounted upon the side panel I and serves as a support and shield for the control mechanism. Mounted within said control box, upon the forward end thereof, are three hydraulic control valves I08, one of which is disposed in each of the hydraulic fluid lines intermediate the storage tank (not shown) and the separate piston-and-cylinder units described hereinbefore. Each control valve has two inlet ports (not shown) for connection with the fluid storage tank and two outlet ports I09 for connection with the corresponding piston-andcylinder unit. A piston within each control valve may be moved with relation to said inlet and outlet ports in such manner as to cause fluid to flow from the storage tank into the selected cylinder unit on one or the other sides of the piston contained therein while fluid flows from the opposite side of the piston back to the storage tank. The neutral position of the control valve pistons prevents fluid flow in either direction between the storage tank and the pistonand-cylinder units. This type of control is well known in the art and therefore complete description thereof is considered unnecessary.

Piston rods H0, secured to one end of each of the control valve pistons, extend outwardly of the control box I98 and are each pivotally secured to the lower end of the hand levers HI, H2 and H3, respectively. Lever III actuates the control valve of the stripper cylinder II, lever H2 actuates the control valve of the toggle cylinder 64, and lever II3 actuates the control valve of the feed cylinder 49. Each of said levers is pivotally secured to a bracket H4 projecting from each control valve to a link H5. The link connection to the levers is made at a point intermediate the handle end and the connection of the piston rods I99, as best shown in Fig. 9 of the drawings.

Lever H2 extends downwardly from the connection of the piston rod H and is provided at its end with a projection pin H6. Said pin engages the slotted end of arm II'I, which is attached firmly at the opposite end to a pin H8. Pin H8 is mounted for rotation in bracket H9, which is secured to the front panel of the control box IIJi. A second arm I29 is secured firmly at one end to pin I I3 and at the opposite end it is joined pivotally to the lower end of link rod I2I. The upper end of link rod I2I is pivotally connected to the rear end of a lever I23 which is mounted pivotally intermediate its ends upon a bracket I22 secured to the base member 5. The forward end I24 of lever I22 is notched transversely to form a latch. Said latch is proportioned and arranged to receive resiliently the hooked end of catch I25 which is secured pivotally intermediate its ends to a bracket I25. A plurality of tension springs I2? interconnect the upper end of the catch with a plate I28 secured pivotally to the bracket I25 for holding said catch resiliently in a vertical position. The bracket I26 is mounted for lateral adjustment upon the tubular shield 49, whereby the engagement of the catch and latch may be selected controlled.

Referring now to Fig. 9 of the drawings, piston rods I29 are secured to the inner ends of the pistons of the control valves I958. The outer end of each of these piston rods I29 is pivotally secured to the upper ends of three lever arms I29 which are mounted pivotally at their lower ends on brackets I3I secured to the base of the control box I01. A rearwardly projecting flange at the upper nd of each arm I39 supports an idler wheel I32, each of which is adapted to engage the peripheral surface of a cam wheel I33. The three cam wheels are mounted in spaced relation upon a shaft I34 which is driven by means of interengaging gears I35 and I36. Gear I36 is secured to the power take-off shaft I31 of a gear reductioniunit I38 which is connected through pulleys I39 and I49 and belt I4I to the control drive motor I42.

The cams I33 which govern the automatic sequence of operation may be disengaged from the idler wheels I32 whenever manual operation of the levers III, H2 and H3 is desirable. The levers I43 upon which the shaft I34 is journaled are mounted rotatably at their lower ends upon the ends of the power take-0E shaft I31. The upper ends of said levers are connected through link I44 to a hand lever I45 intermediate the ends of the latter. Said hand lever I45 is mounted pivotally on the side of the control box I9! and projects outwardly therefrom for convenient manipulation. A second hand lever I46 is pivotally mounted intermediate its ends upon a bracket I41 extending from the front panel of the control box. Said lever I46 projects inwardly through a slot in the control box and is connected pivotally at its inner end through link I48 to lever I49. Lever I49 is pivotally mounted at its lower end to bracket I3I forwardly of the connection of lever arms I30. Lever I49 is provided at its upper end with three rearwardly projecting tubes I50. The rearward end of each of said tubes is provided with vertical slots i5I, each arranged to receive one of the lever arms I39 therein. Coil springs I53 are disposed within the tubes between the levers I49 and the lever arms I30 and function to urge the latter rearwardly to provide positive contact between the idler wheels I32 and the cams I33. Thus, by rotating hand levers I45 and I46 in a clockwise direction, as viewed in Fig. 9, the levers I39 and the cams I33 are drawn apart and out of contact with each other, whereby operation of the block making machine is reduced to manual control.

The operation of the concrete block making machine described hereinbefore, which also exemplifies the method embodying our invention, is as follows:

Let it be assumed for purposes of explanation that the various elements of the machine are arranged in the position shown in Fig. 2 of the drawings. In this position, with the hydraulic fluid pump (not shown) and the control valve motor I42 in operation, the toggle beam 8, the pallet beam 2| and the pressure beam 4'! are in their upwardmost position and springs 24 hold the pallet 29 resiliently against the bottom of the mold 3I. The carrier box 31 is arranged below the supply hopper 36 and is thus filled with the concrete mixture to be formed into blocks. The types of blocks most common in the art and which are readily produced by our machine are those composed either of pumice stone or those of sand and other aggregate. Said concrete mixture contains sufficient water for producing the desired chemical reaction, but insufficient water to form a wet mix. In other words, the mixture is in the so-called dry state, in which considerable pressure is required to cause the particles to cohere. The mixture flows freely, therefore, and is capable of being admitted into the mold and vibrated and compressed quickly into block form.

In automatic operation, the cam I33 which actuates the control valve I08 of the feed cylinder 46 now moves to the position in which hydraulic fluid flows into the rearward end of the feed cylinder. The carrier box 31 thus moves forwardly and becomes superimposed over the mold 3l and the plate 43 closes the bottom of the supply hopper 36. Simultaneously therewith, contact arm I05 engages the toggle switch I04 which completes the circuit through the closed switch I06 and the magnetic switch (not shown) to energize the vibrator motor 88. In the type of vibrator construction illustrated in Figs. 1 to 6, inclusive, the carrier box 31, the mold 3|, the pallet 29, and the pallet table 25 are caused to move through an elliptical path in the direction of movement of belts 85, as indicated by the arrows in Fig. 6. The adjustment screws 21 areset to provide a clearance between their upper ends and the bottom of the pallet table equal in magnitude to the vertical movement of the vibrator rods 63, as determined by the degree of offset of the driven 10 and thus move the pressure beam 41 and shoes 61 downwardly over the mold. Coil springs 55 function during this movement to prevent excessive pressure to be exerted by the shoes 61 upon the concrete material in the mold. The action desired is to have the vibratorymotion cause most of the settling and uniform distribution of the concrete material and to supply sufficient pressure on the shoes to maintain a level surface and uniform pressure throughout the depth of the mold. When the toggle joint is fully straightened, as shown in Fig. 3 of the drawings, vibration continues to pack the concrete ma terial until little, if any, pressure is exerted by the shoes 61 upon the compressed blocks in the mold. At this point the cam I33 operates the a control valve I08 of the stripper cylinder II,

shaft 8| from the center of the cam bushing 80. I

Ordinarily the rods 68 may bend or whip axially during their rapid movement and thereby cause greater tippingof the mold than normally should occur, but the setting of the screws 2'! limits the magnitude of such tipping action to a constant value.

In the modified form of vibrator illustrated in Figs. 10 to 12, inclusive, the arrangement of parallel links I00 and I 02 prevents the tipping action and permits motion of the mold only in vertical and horizontal planes. The magnitude and direction of the horizontal movement is made variable by adjusting the position of the slide members 94 relative to the pivot axis 9| of the mold. Thus, when the slide member is positioned above the pin 9i, the mold rotates in a clockwise direc tion, as viewed in Fig. 10, while the direction is reversed when the slide member is situated below the pin. It is evident that only vertical motion results when the slide member 94 lies in coincidence with the pivot axis 9| of the mold.

The vibratory motion causes the dry concrete material to fall from the carrier box into the mold. It generally occurs that a majority of the concrete falls into the near side of the mold, that is, the side over which the carrier box first moves during its forward travel. The direction of the vibratory movement causes the concrete material thus arranged to move forwardly in the mold in the direction of the arrow shown in Fig. 6 to fill the latter to an even depth. Fluid now flows into the forward end of the feed cylinder 45 and causes the carrier box to be retracted. By proper setting of the gate 4|, concrete material in excess of the quantity required to form the blocks is removed. It is to be noted that the vertical slots 42 which overlie the core bars 32 are enlarged to permit retention in the mold of a quantity of concrete material sufficient to fill the void produced immediately below said core bars. It may occur in the manufacture of some types of blocks that the quantity of concrete material carried by the box 31 is insufficient to fill said mold. In such cases, the cam I33 may be designed to permit a second full or partial load to be added to the mold.

After the mold has been filled and the excess concrete material drawn off, the vibration is continued and fluid pressure is admitted into the rearward end of the toggle cylinder 64. The piston rod 63 moves outwardly, causing the

arms

58 and 59 of the toggle joint to straighten out causing fluid to be admitted to the upper end of the latter. Piston rod I0 thereupon moves downwardly, pulling the toggle beam 8, the pallet beam 2|, and the pressure beam 41 with it.

As the pallet beam 2| moves downwardly, the switch I06 opens and breaks the circuit to the vibrator motor 88. Said switch may be arranged to stop the vibration at any point along the downward movement of the pallet beam, in contrast with the requirement of prior machines that vibration must be stopped before ejection of the blocks from the mold is started. It has been found desirable in many instances of operation of the device herein described to continue vibration during full extraction of the blocks from the mold. In these cases, it has been observed that the troweling action of the vibrating mold against the sides of the blocks produces a smoother surface. Whereas in conventional machines extraction during vibration results in fracture of the blocks, the blocks produced by the machine described herein exhibit no structural deformities or weakness. Although the reasons for this difference are not completely understood, it is believed to result from the precise control of vibratory motion attainable with the present device.

Provision is made for cushioning the above assembly against shock as it reaches its lowermost position, thus preventing breaking of the blocks which rest freely upon the pallet 29. As the assembly reaches the position shown in Fig. 4, catch I25 contacts the notched end of lever I23 and pivots the latter in a counterclockwise direction. Lever I I2 thereupon moves rearwardly to change the flow of fluid through control valve I08 to the frontend of the toggle cylinder 64. The

arms

58 and 59 of the toggle joint thus movetogether slightly to raise the toggle rods 5!] and pressure beam t? whereby the pressure shoes 68 are elevated from the blocks 30. Simultaneously with the changing of fiow of fluid in the toggle cylinder 6d, the volume of hydraulic fluid previously admitted to the upper end of the stripper cylinder is reduced by one-half, the remaining one-half being fed to the toggle cylinder. The downward pull of the stripper cylinder piston is thereby reduced and the toggle beam 8 strikes the bumpers f? with a diminished force. The bumpers I! then move downwardly against the compression of the coil springs 20 into abutment with the pedestals I5, thereby bringing the assembly to a smooth halt.

As hydraulic fluid was admitted to the front endof the toggle cylinder 64, as explained in the preceding paragraph, the toggle joint began to close and the pressure beam 41 started to move upwardly. Catch I25, which is mounted upon vibration.

Fluid flow to the toggle cylinder 64 now ceases .and the pressure beam 41 remains stationary. In

this position the blocks 30 are ready for removal from the pallet table 25. This may be accomplished by removing the pallet 29 with the blocks resting thereon by'hand. A preferred method,

however, is to provide automatic means for feeding a new pallet onto the table 25 whereby the loaded pallet is pushed outwardly upon a conveyor which transports the formed blocks to a storage place where final curing is effected. Such automatic means forms no part of the present invention and is therefore not described in detail here.

After the blocks 30 and their supporting pallet 29 have been removed from the machine and a new pallet has been arranged upon the table 25, the cam 33 which operates the control valve I08 of the stripper cylinder II moves to the position at which hydraulic fluid flows into the bottom side of said stripper cylinder. This causes the toggle beam 8, the pallet beam ZI, and the pressure beam 41 to rise upwardly through the position shown in Fig. 1 to the fully elevated position shown in Fig. 2. During rise of the pressure beam, catch I25 disenga'ges from lever I23 without moving the latter, and hence without disturbing the neutral setting of hand lever H2. The cam I33 which operates the control valve of the toggle cylinder 54 now moves to admit hydraulic fluid into the forward end of the toggle cylinder. This causes the toggle joint to close and thus to move the toggle rods 50 upwardly to their fully extended position whereby the pressure shoes 61 are raised clear of the mold 3| and carrier box 31,. The various elements of the machine have thus moved through one complete operating cycle and. are returned to the position shown in Fig. 2.

' Although the operation has been described herein, with reference to the automatic sequence control system, it is evident that said operation may be performed manually by merely moving levers I45 and I46 to the positions wherein the cams I33 are operatively disconnected from the control valves I08. Manual control of the operating sequence is desirable, particularly in cases where. inconsistencies occur in the texture of the 'concrete mixture. It frequently happens, for example, that the mixture deposited in supply hopper 36 contains an excess of water. Such a mixture exhibits reluctance to flow, and thus the mold is properly filled only after an extended period of On the automatic sequence, blocks prepared from the wet mixture become distorted and weak after ejection from the mold. It has been the practice heretofore to remove the wet mix from the hopper and discard it where changes in timing of the various molding steps were not obtainable. This practice is expensive, for not only are large quantities of material wasted, but considerable time is spent in clearing the hopper and mold and preparing a new mixture of proper consistency. The use of our machine, however, permits rapid change from automatic to manual control, and thus variations in mixtures are readily accommodated without waste or other additional expense.

We claim:

1. In a machine for making concrete blocks ineluding a mold, a vertically movable stripper assembly for removing blocks from said mold, a pressure beam movable vertically both with said stripper assembly and independently of said assembly, and a carrier box movable laterally over said mold for filling the latter, the combination therewith of hydraulic piston-and-cylinder power units for actuating each of said movable elements independently, control valves in the hydraulic systems of said power units, hand levers on said control valves for operating the latter manually, cam members mounted retractably adjacent said control valves, power means for rotating said cam members, link means detachably engaging said cam members and said control valves for operating the latter automatically, resilient lever means mounted retractably adjacent said link means for urging the latter into engagement with said cam members, and hand lever means connected to said cam members and to said resilient lever means for manually engaging and disengaging said cam members and control valves selectively.

2. In a machine for making concrete blocks including a mold, a vertically movable stripper assembly for removing blocks from said mold, a pressure beam movable vertically both with said stripper assembly and independently of said assembly, and a carrier box movable laterally over said mold for filling the latter, the combination therewith of hydraulic piston-and-cylinder power units for actuating each of said movable elements independently, control valves in the hydraulic systems of the piston-and-cylinder power units, hand levers on said control valves for operating the latter manually, rotating cam members engageable with said control valves for operating the latter automatically, power means for rotatingsaid cam members, and lever means engaging said cam members for controlling manually the engagement and disengagement of said cams and said control valves, the cam members operating the control valves of the power units of said stripper assembly and said pressure beam being proportioned and arranged to divide the hydraulic power between said units for braking the downward movement of said stripper assembly adjacent the lowermost position of the latter.

3. In a machine for making concrete blocks, the combination of a frame, a mold suspended in said frame, a supply hopper mounted above and adjacent said mold, a carrier box mounted retractably above said mold and below said hopper for movement therebetween, hydraulic piston and-cylinder power means mounted on said frame and engaging said carrier box for moving the latter between said mold and said hopper, laterally spaced sleeves movable vertically on said frame, a. toggle beam connecting the lower ends of said sleeves, a pallet beam below said mold connecting intermediate portions of said sleeves, said sleeves and attached beams forming a stripper assembly for removing blocks from said mold, a pressure beam above said mold overlying the upper ends of said sleeves, toggle rods secured at their upper ends to said pressure beam, toggle joint means interconnecting the stripper assembly and the lower ends of said toggle rods, hydraulic piston-and-cylinder power means movable with said stripper assembly and operatively engaging said toggle joint means for moving the toggle rods and attached pressure beam vertically independent of said stripper assembly, hydraulic piston-and-cylinder power means mounted on said frame for moving the stripper assembly and pressure beam vertically, control valves in the l3 hydraulic systems of the piston-and-cylinder power means, hand levers on said control valves for operating the latter manually, rotating cam members engageable with said control valves for operating the latter automatically, power means for rotating said cam members, and lever means engaging said cams for controlling manually the engagement and disengagement of said cams and said control valves.

4. In a machine for making concrete blocks, the combination of a frame, a mold suspended in said frame, a driven shaft mounted on said frame, power means for driving said shaft, spaced vibrator rods mounted eccentrically at one end upon said driven shaft, the opposite ends of said vibrator rods being secured pivotally to said frame, said vibrator rods being secured adjustably intermediate their ends to opposite sides of said mold, whereby rotation of said driven shaft causes elliptical movement of the mold.

5. In a machine for making concrete blocks, the combination of a frame, a mold suspended in said frame, laterally spaced sleeves movable vertically on said frame, a pallet beam below said mold connecting intermediate portions of said sleeves, a pallet support mounted resiliently upon said pallet beam, adjustable screw means between the pallet beam and said pallet support for limiting the degree of tipping of the latter, a driven shaft mounted on said frame, power means for driving said shaft, spaced vibrator rods mounted eccentrically at one end upon said vibrator rod being secured pivotally to said frame, said vibrator rods being secured intermediate their ends to opposite sides of said mold, whereby rotation of said driven shaft causes elliptical movement of the mold.

6. In a machine for making concrete blocks including a mold, a vertically movable stripper assembly for removing blocks from said mold, a pressure beam movable vertically both with said stripper assembly and independently of said assembly, and a carrier box movable laterally over said mold for filling the latter, the combination therewith of hydraulic piston-and-cylinder power units for actuating each of said movable elements independently, and automatic control valve means for dividing the hydraulic power between the power means of said pressure beam and said stripper assembly at a point adjacent the lowermost position of said assembly for braking the downward movement of the latter.

'7. In a machine for making concrete blocks, the combination of a frame, a mold suspended in said frame, laterally spaced sleeves movable vertically on said frame, a toggle beam connecting the lower ends of said sleeves, a pallet beam below said mold connecting intermediate portionsof said sleeves, said sleeves and attached beams forming a stripper assembly for removing blocks from said mold, a pressure beam above said mold overlying the upper ends of said sleeves, toggle rods secured at their upper ends to said pres sure beam, toggle joint means resiliently interconnecting the stripper assembly and the lower ends of said toggle rods, hydraulic power means movable with said stripper assembly and operatively engaging said toggle joint means for moving the toggle rods and attached pressure beam vertically independent of said-stripper assembly, hydraulic power means mounted on said frame for moving the stripper assembly and pressure beam vertically, and control valve means for dividing the hydraulic power between the power means of said toggle rods and said stripper assembly at a point adjacent the lowermost posi- 14 tion of said assembly for braking th downward movement of the latter.

8. In a machine for making concrete blocks, the combination of a frame, a mold suspended in said frame, laterally spaced hollow sleeves movable vertically on said frame, a toggle beam connecting the lower ends of said sleeves, a pallet beam below said mold connectin intermediate portions of said sleeves, said sleeves and attached beams forming a stripper assembly for removing blocks from said mold, a pressure beam above said mold overlying the upper ends of said sleeves, toggle rods mounted slidably in said hollow sleeves and secured at their upper ends to said pressure beam, toggle joint means interconnecting the stripper assembly and the lower ends of said toggle rods, hydraulic piston-and-cylinder power means movable with said stripper assembly and operatively engaging said toggle joint means for moving the toggle rods and attached pressure beam vertically independent of said stripper assembly, hydraulic piston-and-cylinder power means mounted on said frame for moving the stripper assembly and pressure beam vertically, and automatic control means for dividing the hydraulic power between the power means of said toggle rods and said stripper assembly at a point adjacent the lowermost position of said assembly for braking the downward movement of the latter.

9. In a machine for making concrete blocks, the combination of a frame, a mold suspended in said frame, laterally spaced sleeves movable vertically on said frame, a toggle beam connecting the lower ends of said sleeves, a pallet beam below said mold connecting intermediate portions of said sleeves, said sleeves and attached beams forming a stripper assembly for removing blocks from said mold, a pressure beam above said mold overlying the upper ends of said sleeves, toggle rods secured at their upper ends to said pressure beam, toggle joint means interconnecting the stripper assembly and the lower ends of said toggle rods, hydraulic piston-and-cylinder power units for actuating each of said movable elements independently, resilient cushion means between the frame and the stripper assembly for braking the downward movement of said assembly adjacent its lowermost point of travel, and control means for dividing the hydraulic power 'between the power means of said toggle rods and said stripper assembly at a point adjacent the lowermost position of said assembly for braking the downward movement of the latter.

10. A machine for making concrete blocks comprising the combination of a frame, a mold suspended in said frame, a vertically movable stripper assembly for removing blocks from said mold, a pressure beam movable vertically both with said stripper assembly and independently of said assembly, a carrier box movable laterally over said mold for filling the latter, hydraulic piston-and-cylinder power units for actuating each of said movable elements independently, control valves in the hydraulic systems of the piston-and-cylinder power units, hand levers on said control valves for operating the latter manually, rotating cam members engageable with said control valves for operating the latter automatically, power means for rotating said cam members, lever means engaging said cams for controlling manually the engagement and disengagement of said cams and said control valves, the cam members operating the control valves of the power units of said stripper assembly and said pressure beam being proportioned and arranged to divide the hydraulic power between said units for braking the downward movement of said stripper assembly adjacent the lowermost position of the latter, resilient spring means between the frame and the stripper assembly for braking the downward movement of said assembly adjacent its lowermost point of travel, and motor driven vibrator means secured to said mold for moving the latter within adjustable limits.

11. A machine for making concrete blocks comprising the combination of a frame, a mold suspended in said frame, a vertically movable stripper assembly for removing blocks from said mold, a pressure beam movable vertically both with said stripper assembly and independently of said assembly, a carrier box movable laterally over said mold for filling the latter, hydraulic piston-and-cylinder power units for actuating each of said movable elements independently,

control valves in the hydraulic systems of the piston-and-cylinder power units, hand levers on said control valves for operating the latter manually, rotating cam members engageable with said control valves for operating the latter automatically, power means for rotating said cam members, lever means engaging said cams for controlling manually the engagement and disengagement of said cams and said control valves, the cam members operating the control valves of the power units of said stripper assembly and said pressure beam being proportioned and arranged to divide the hydraulic power between said units for braking the downward movement of said stripper assembly adjacent the lowermost position of the latter, a driven shaft mounted on said frame, power means for driving said shaft, and spaced vibrator rods mounted eccentrically at one end upon said driven shaft, the opposite ends of said vibrator rods being secured pivotally to said frame, said vibrator rods being secured intermediate their ends to opposite sides of said mold, whereby rotation of said driven shaft causes e1- liptical movement of the mold.

12. A machine for making concrete blocks comprising the combination of a frame, a mold suspended in said frame, a vertically movable stripper assembly for removing blocks from said mold, a pressure beam movable vertically both with said stripper assembly and independently of said assembly, a carrier box movable laterally over said mold for filling the latter, hydraulic piston-and-cylinder power units for actuating each of said movable elements independently, control valves in the hydraulic systems of the piston-and-cylinder power units, hand levers on said control valves for operating the latter manually, rotating cam members engageable with said control valves for operating the latter automatically, power means for rotating said cam members, lever means engaging said cams for controlling manually the engagement and disengagement of said cams and said control valves, a driven shaft mounted on said frame, power means for driving said shaft, spaced vibrator rods mounted eccentrically at one end upon said driven shaft, guide members mounted pivotally on opposite sides of said mold, the terminal ends of said vibrator rods being secured to said guide members, slide members mounted movably on said guide members,

adjustable link means interconnecting said slide members and said frame, and link means pivotally interconnecting said mold and said frame for permitting movement of said mold only in vertical and horizontal planes.

13. A machine for making concrete blocks comprising the combination of a frame, a mold suspended in said frame, motor driven vibrator means secured to said mold for moving the latter vertically and horizontally within adjustable limits, laterally spaced hollow sleeves movable vertically on said frame, a toggle beam connecting the lower ends of said sleeves, a pallet beam below said mold connecting intermediate portions of said sleeves, said sleeves and attached beams forming a stripper assembly for removing blocks from said mold, a pressure beam above said mold overlying the upper ends of said sleeves, toggle rods mounted slidably in said hollow sleeves and secured at their upper ends to said pressure beam, toggle joint means interconnecting the stripper assembly and the lower ends of said toggle rods, hydraulic power means movable with said stripper assembly and operatively engaging said toggle joint means for moving the toggle rods and attached pressure beam vertically independent of said stripper assembly, hydraulic power means mounted on said frame for moving the stripper assembly and pressure beam vertically, resilient cushion means between the frame and the stripper assembly for braking the downward movement of said assembly adjacent its lowermost point of travel, a supply hopper mounted above and adjacent said mold, a, carrier box mounted retractably above said mold and below said hopper for movement therebetween, hydraulic power means mounted on said frame and engaging said carrier box for moving the latter between said mold and said hopper, control valves in the hydraulic systems of said power units, hand levers on said control valves for operating the latter manually, rotating cam members engageable with said control valves for operating the latter automatically, power means for rotating said cam members, and lever means engaging said cams for controlling manually the engagement and disengagement of said cams and said control valves, the cam members operating the control valves of the power units of said stripper assembly and said pressure beam being proportioned and arranged to divide the hydraulic power between said units for braking the downward movement of said stripper assembly adjacent the lowermost position of the latter.

RUSSELL B. NELSON. MILES DAVIES. FRED NETH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS