US2451167A - Block molding machine - Google Patents

Description

Oct 12, 1948. A. T. JOHNSON 2,451,167

BLOCK MOLDING MACHINE Filed June 3, 1947 3 Sheets-Sheet 1 7 I IN V EN TOR.

flrazken f r/bA/YJO/Y Z 7 BY Oct. 12, 1948. A, OHNSON 2,451,167

BLOCK MOLDING v MACHINE IN V EN TOR.

A TTO/FNEYJ et. 12, 1948. JQHNSON 2,451,167

BLOCK MOLDING MACHINE Filed June 3.- 1947 3 Sheets-Sheet I5 IN V EN TOR.

Patented Oct. 12, 1948 UNITED STATES PATENT OFFICE 2,451,167, BLOCK MOLDING MACHINE Andrew T. Johnson, Las Vegas, Nev. 7 Application June a, 1947, Serial No. 752,119

Claims. 1 This invention relates to block molding machines, and more particularly to a machine for pressure-molding concrete building blocks.

A main object of the invention is to provide a novel and improved concrete block molding machine which is simple in construction, easy to operate and reliable in performance. 7 A further object of the invention is to provide an improved block molding machine of the hydraulic pressure type which is inexpensive to manufacture, sturdy in construction and Wherein the dimensions and texture of the product can be accurately controlled.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a front elevational view, partly in cross-section of a building block molding machine constructed in accordance with the present invention.

Figure 2 is an enlarged side elevational View, partly in cross-section, of the top portion of the block molding machine of Figure 1.

Figure 3 is a top plan View of the main body of the machine of Figure 1 illustrating the means employed therein for securing the core supporting frame therein.

Figure 4 is an enlarged front elevational detail view of the mold filling box and its support ing' table, as employed in the machine of Figure 1. a

Figure 5 is a front elevational view of the machine of Figure 1 showing its connections to a source of hydraulic fluid and pressure generating means therefor as employed in the present invention.

Referring to the drawings, ll comprises the frame'of the machine, the frame consisting of longitudinal base channels l2 and transverse base channels l3 rigidly secured together to define a rectangular bottom support for the machine, the channel flanges being directed outwardly, corner posts 14 secured to the inner corners of said bottom support and rising vertically therefrom, and a top rectangular'frame section comprising longitudinal" channels i5, transverse channels i6 secured at its inner 'corners to the top portions of the posts I4. Connecting the bottom transverse channels I3 is a horizontal bottom plate member l! on which'is secured a pair of cylinders I8, I 8. Each cylinder has a top wall l9 which is formed at itscenter with a vertical bore Slidably engaging the walls of each cylinder is a piston 2| having 2.

l5 and stem portion 22 vertically slidable in bore 20. Piston 2| and stem 22 are formed with a central vertical bore 23 in which is s-lidably positioned a plunger rod 24 formed at its top end with an enlarged head 25. Connected to the bottom wall of each cylinder 3 at its center is a fluid inlet conduit 26, and connected to the junction of said conduits is a common fluid supply pipe 21. Each cylinder is connected at its upper wall portion to a vent chamber 28 having an air vent tube 29 and a fluid overflow tube 30. Overflow tube 30 is connected to the fluid reservoir 3|, shown in Figure 5.

The upper portion of bore 23 is formed with an annular groove 32 connected by a passage 33 in stem 22 to the lower outer portion of said stem, said passage 33 opening into the upper portion of the cylinder [8 when the parts are in the positions shown in Figure 1. A passage 34 in the top wall member I9 connects the intermediate portion of bore 20 with the top of the cylinder chamber 18 and is arranged so that when piston 2i is raised by fluid pressure to its uppermost position in said chamber, as determined by a stop shoulder 35 carried by said piston, the lower end of passage 33 registers with the upper end of passage 34. This by-passes any fluid which has leaked past'plunger bar 24 back to the upper portion of the main cylinder chamber. A stop screw 36 is provided in the bottom wall of each cylinder I8 for adjusting the lowermost position of piston 2|.

Overlying and supported on the enlarged heads, 25, 25, is a bar member 31 which is vertically movable, responsive to the upward movement of said heads and is guided in its upward movement by vertical threaded bars 38 secured to the opposing horizontal flanges of the upper and lower transverse channel i6 and I3 and being slidably received in notches 39 formed inthe end portions of the bar member 31.

Stop nuts shown at 40 and 4| respectively limit the upward and downward movements of bar member 31, said stop nuts being threaded on the vertical bars 33 and being vertically adjustable thereon.

Secured in the top rectangular enclosure defined by the upper longitudinal channels I5, I5 and the upper side channels I5 is a rectangular box-like frame 42 which is open at its top and bottom and is provided with transverse partitions 43, 43 dividing the frame into three equal mold box compartments. The frame 42 is adjustably secured in position by respective front and side clamping plates 44 and 45 engaged by clamping screws 46 threaded through the respective front channel I5 and right side channel I6.

Secured to the bottom of the frame 42 by longitudinal bar elements 41 are spaced core blocks 48, two such core blocks, being provided in each mold box compartment. Overlying the end portions of the bar elements in each mold box compartment and slidably fitting around the core blocks and inside the walls of the compartment is a push block. 49.] Overlying the push block is 'a pallet 50 on which the moldable material is adapted to be deposited. Secured to the bottom of each push block 49 substantially centrally As shown in Figure 5, 3| designatesthe fiuid reservoir. A conduit 66 connects reservoir 3| to a pump 61. The outlet conduit '68 of said pump is connected through an accumulator tank 69 to a conduit 10. Conduit is connected to conduit 21 through a valve II which'is manually controlled by a valve rod I2. 1 Also connected to conduit 21 is an exhaust pipe 13 opening in reservoir I 31, said exhaust pipe including a valve 14 which thereof and depending therefrom is a vertical;

push rod 5| provided at its bottom end with an adjustable stop screw 52. The push rodsfi'lslid ably pass through a horizontal guide plate 53 secured to the frame II, said guide plate having upstanding guide collars 54 encircling the respec-' tive push rods '5I. Subadjacent the stop screws 52 :is the pressure equalizing bar'3I against which the pistonheads '25 bear upwardly whenfluid underpressure is introduced into the cylinders I8. Bar 31 is freely vertically movable within the frame and is formed with the guide notches 39, as above described, cooperating with the vertical guide bars-38. 1 r

' Pivotally secured to the top transverse side edge of the frame I I bya transverse hinge-1311155 is'atop cover plate 56 provided with a counterweight 5'! to facilitate opening the cover plate. Pivoted to the opposite free edge portion of the cover plate is a latch 58 adapted to hook under thetop ,fiange of the adjacent side channel IIB to lock the cover plate in closed position. The. cover plate carries .on its bottom surface pressure lugs 59 fitting around'the core blocks 48 in the space between said blocks and the mold box walls. Secured to the rear top longitudinal channel l5 by triangular gussets 60 is a rearwardly extending horizontal table plate 6| substantially flush with the top flange surfaces ofthe channels I5, I5; The table plate is :formed with parallel transverse guide channels "62; 62 and slidably engaged therein are the lateral'ribs 63, 63 carried by a box member 64 'which'is thereby transversely slidable on table plate 6 I Box mem ber 64 has sidehandles 65', 65 for manipulating the'box'member backwardly and forwardlyw'lth respect to the guide channels 6 2, 62. The bottom and top of the box member 64 are-open. "In charging the mold box compartment,'box member 64 is first positioned on table plate BI in the position shown in Figure 2 and is filled with the moldable material; With the push rods :5I in de pressed positions, as shown in Figure 1, the box member 64 is then moved forwardly until it over} lies the mold box compartments; whereby the moldable material drops into said compartments. The box member 64 is then moved back rear- Wardly of its starting position, whereby excess moldable material is struck off from the top of the mold box compartments. The inoldbox com-v partments arethen ready for the molding operation.

In molding the blocks, the cover member 55 is swung to closed position and latched thereini Lugs 59 act to tamp the moldable material downwardly somewhat preliminary to the actual appli cation of molding pressure. With covermember 56 locked in closed position, fluid under pressure is admitted to cylinders I8 through conduits 26, causing the main pistons 2| to rise, upward force being transmitted at heads 25 to the equalizer bar is manually controlled by a valve rod I5. Con-. nected ahead of valve II to conduit 10 is a conduit 16 opening into reservoir 3I and including a relief valve 11 adapted to open when the pressure in conduit I0 rises to a limit value substantially Wall of the cylinder.

higher than the working pressure value. The conduit connecting tank' 69 to conduit I0 includes amanual shut-off valve 18. Ajby-Passconduit '19 connects conduit 58 to conduit Illand includes a manual shut-off .valve 80. By closingnzeiither Valve 80 orvalve I8, either -by.-pass;conduit T9 orlaccumulator tanks-9 may be excluded-from the. fluid pressure line. When tank 59: is emf;

ployed, it acts to accumulate a large, amount of fluid under pressure in the fluid-supply system and substantially eliminates pressure fluctuations inthe'fluidpressure line.

In order tocompress the moldable materiaLas' above described, valve I4 is closed and'valve II. is opened, so that fluid underpressurefenters the cylinders IB, Piston .ZI in each cylindermoves upwardly until shoulder35 thereof abuts the'top At this point valve His closed momentarily and cover ,member is une; latched and raised to a vertical .positiom -being held therein by the counter-weight 51.. Valve "II is again opened, and plunger 24 of each cylinder is forced upwardly by the additional fluid under pressure entering the cylinders. Equalizer. barl 31 is moved upwardly until further. upwardmovee ment thereof is: prevented by the stoplinutsifll. This elevates the push blocks 49 and'raisesthe' formed blocks out of the mold box compartments; the pushblocks being finally in positions suchas shown in Figure 2.

Secured tothe front wall of the box member 64 is a forwardly projecting horizontal'lug BI"; .To' receive a new charge of moldable material, box member 64 is moved forwardly until its "bottom forward edge portion 82 abuts the adjacent t'op edge portions .of the push blocks 49. Thelugfl by this motion moves overthetop surface ofthe .push blocks and pushes thepallet-me'mbersfifl carrying the finished blocks 83 forwardly/"sov that the pallet members and finished-blocks may bere- 1 When unloading is 7 moved from the machine. 7 completed, valve .II is closed and valve 1441's opened, .allowingthe fluid in the cylinders .I8 to" exhaust into the reservoir 3 I and allowin the Dis;v tons therein to return to their startin positions: and the push blocks 49 to drop back to'theirbot tom positions in the mold box compartments. New pallets are then inserted thereonand-the process may be repeated' The machine is not limited to the boxes illustrated and described above. Any size and shape of mold box and corresponding pressure:

transmitting members therefor may be employed.

in place of the frame 42 and its associatedpre sure transmitting components.

The. length of the power stroke and the raising stroke may be readily adjusted, by .respec tively adjusting the stop screws 36 and the stop nuts 40 and 4 l. The depression of equalizer member 13 is limited by the adjustment of lower stop nuts 4|, thus controlling the amount of material that can be placed in the mold box compartments before compression.

By the above described adjustments the power stroke and the subsequent block ejection stroke of the respective pistons 2| and 24 can be controlled within very exact limits.

Accurate sizing is obtained on all exterior and interior surfaces of the finished blocks due to the smooth vertical surfaces employed on the mold box walls and cores and the polishing action produced on the blocks during the process of upward ejection of the blocks along said smooth vertical surfaces.

The equalizer bar 3'! insures that the compressive load will be equally distributed on the heads 25 and that said heads will advance in unison during the compression stroke. If one piston advances faster than the other the bar 31 tilts and engages the edge portions of the piston heads 25. This causes the leading piston to immediately assume more than its normal proportion of load, and since both pistons are of equal size and are actuated by a common pressure source, the piston carrying the reater load will be retarded until the other piston advances to the point where the bar 31 will return to horizontal position across the wide faces of the piston heads. From this point the pistons will again advance in unison.

The use of the energy-storing accumulator tank 69 makes it possible to employ a relatively small capacity pump 61.

While a specific embodiment of a block molding machine has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention other than as defined by the scope of the appended claims.

What is claimed is:

l. A pressure molding machine for forming building blocks comprising a rectangular box-like frame, a pair of cylinders secured vertically in the lower portion of the frame, a main piston in each cylinder, an auxiliary piston telescoped in said main piston and vertically slidable therein, the main piston having a stem portion slidably fitting the top wall of the cylinder, an enlarged head on the top end of each auxiliary piston, a bar member overlying the piston heads, means guiding said bar member for vertical movement, a mold box secured in the upper portion of the frame, an upwardly movable plunger slidably fitting said mold box, and a depending vertical push rod carried by said plunger and engaging the bar member at its bottom end.

2. A block molding machine comprising a rectangular box-like frame, a vertical cylinder secured in the lower portion of the frame, a main piston in said cylinder having a stem passing slidably through the top wall of said cylinder, an auxiliary piston telescoped in said main piston and stem and vertically slidable therein, an enlarged head on the top end of said auxiliary piston, a pressure transmitting member overlying said head, a mold box secured in the upper portion of the frame, a releasable closure for the top of said mold box, an upwardly movable plunger slidably fitting said mold box and defining a bottom closure therefore, and a depending rod member carried by said plunger and engaged at its bottom end with said pressure-transmitting member,

3. A block molding machine comprising a rectangular box-like frame, a pair of vertical cylinders secured in the lower portion of said frame, a main piston in each cylinder having a stem passing slidably through the top wall of said cylinder, an auxiliary piston telescoped in each main piston and stem and vertically slidable therein, an enlarged head on the top end of each auxiliary piston, a tiltable bar supported on said enlarged heads, a mold box secured in the upper portion of the frame, a releasable top closure for said mold box carried by said frame, a vertically movable plunger slidably fitting said mold box and defining a bottom closure therefor, and a depending rod member rigidly secured to said plunger and engaging the tiltable bar at its bottom end.

4. A block molding machine comprising a reco tangular box-like frame, a pair of vertical cylinders secured in the lower portion of said frame, a main piston in each cylinder having a stem pass ing slidably through the top wall of said cylinder, an auxiliary piston telescoped co-axially in each Of said main pistons and vertically slidable therein, a tiltable bar supported on the top ends of the auxiliary pistons, means carried by the frame for guiding said tiltable bar for vertical movement, a mold box secured in the upper portion of the frame, a releasable top closure for said mold box pivotally secured at one end to a top edge of the frame, a vertically movable plunger slidably fitting said mold box and defining a bottom closure therefor and a depending rod member rigidly secured to said plunger and engaging the tiltable bar at its bottom end.

5. A block molding machine comprising a rectangular box-like frame, a pair of vertical cylinders secured in the lower portion of said frame, a main piston in each cylinder having a stem pass ing slidably through the top wall of said cylinder, an auxiliary piston telescoped coaxially in each of said main pistons and vertically slidable therein, a tiltable bar supported on the top ends of the auxiliary pistons, means carried by the frame for guiding said tiltable bar for vertical movement, said means being adapted to limit the range of vertical movement of said bar, a mold box secured in the upper portion of the frame, a top closure for said mold box hinged to a top edge of the frame, a vertically movable plunger slidably fitting said mold box and defining a bottom closure therefor, a depending rod member rigidly secured to said plunger and engaging the tiltable bar at its bottom end, a horizontal support carried by said frame adjacent the top edge of said mold box, a pair of parallel guide rails on said support, a shell member slidably engaged with said guide rails and slidable on said support to a position overlying the mold box, and a forwardly projecting horizontal flange carried at the forward wall of said shell member.

ANDREW T. JOHNSON.

N 0 references cited.

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