Combination die and pallet assembly

A combination die and pallet assembly upon which mortarless interlocking cementitious blocks of the type having a plurality of cast male projections thereon, includes a die and pallet plate of solid heavy gage metal with a predetermined array of frustro-conical apertures formed therethrough, and a solid heavy gage metal backing plate removably disposed in contiguous engagement with the bottom surface of the die and pallet plate.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to devices for casting cementitious building blocks 
and more particularly to a combination die and pallet assembly upon which 
mortarless interlocking cementitious blocks are cast with a plurality of 
male projections. 
2. Description of the Prior Art 
Due to the shortage of skilled craftsmen and high labor costs, the search 
for and development of practical and easy to use mortarless interlocking 
cementitious blocks has intensified in recent years. One such block, which 
is beginning to receive general acceptance in the market place, is fully 
disclosed in U.S. patent application Ser. No. 799,725, filed on May 23, 
1977 by the same inventor. Briefly, that mortarless interlocking 
cementitious block is formed with the conventional rectangular 
configuration having a pair of vertical passages formed therethrough, and 
is provided with a plurality of frustro-conical recesses in one of the 
horizontal surfaces, and complimental frustro-conical male projections on 
the opposite surface. The recesses and projections are disposed in 
identical predetermined arrays, and are the block interlocking elements 
which allows the blocks to be laid in an accurately level and aligned 
manner by relatively unskilled laborers. 
These particular mortarless interlocking cementitious blocks are cast in 
special mold box assemblies which are used in conjunction with 
conventional block making machines, with the mold boxes designed to 
simultaneously cast a plurality of such blocks for production efficiency 
purposes. The special mold box assembly includes a special head die which 
forms the frustro-conical female recesses and the top horizontal surface 
in which they are formed, a special mold box die which forms the side wall 
configuration and vertical passages of the block, and a special 
combination die and pallet which forms the frustro-conical male 
projections and the bottom horizontal surface from which they project. 
After the blocks are cast in the above described mold box assembly, the 
head die is raised and the combination die-pallet structure is lowered 
with such lowering causing the blocks to be withdrawn from the bottom of 
the mold box die, and they remain in position atop the die-pallet for 
subsequent handling. The subsequent handling includes transporting of the 
die-pallet structure, with the blocks supported thereon, from the block 
making machine to a kiln for curing. After curing, the die-pallet 
structure and blocks are again transported, this time from the kiln to a 
machine which removes the blocks from the die-pallet structure. From this 
point, the die-pallet structures are routed through suitable cleaning and 
lubricating mechanisms and are returned to the block making machine for 
reuse. 
Since the combination die-pallet structure is an integral part of the 
casting operation with the integrity of the blocks themselves being 
partially dependent thereon, it is extremely important that they be 
dimensionally accurate and stable, perfectly flat, and otherwise precision 
structures. In addition to the required precision and stability, the 
combination die-pallet structures must be: sufficiently strong to resist 
damage which can and sometimes does occur during the above described 
subsequent handling operations, easy to repair in the event of damage, and 
must resist rust out as a result of long periods of exposure to moisture. 
Heretofore, the combination die-pallet structures employed have been sheet 
metal structures fabricated with an upper and a lower plate which are 
welded together with reinforcing ribs interposed therebetween. Basic 
configurations of these laminated honeycombed sheet metal die-pallet 
structures are fully disclosed in U.S. Pat. Nos. 3,998,423 issued Dec. 21, 
1976; 4,078,760 issued Mar. 14, 1978; and 4,093,174 issued June 6, 1978, 
all to the same inventor. These prior art combination die-pallet 
structures although serving the purpose have some shortcomings, in that 
they are relatively expensive to manufacture, are subject to damage such 
as denting, bending and the like, are somewhat difficult to repair, and 
are subject to rust out. 
Therefore, a need exists for a new and improved combination die-pallet 
assembly which overcomes some of the problems and shortcomings of the 
prior art. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, a new and improved combination 
die and pallet assembly is disclosed for use in casting mortarless 
interlocking cementitious blocks, of the type disclosed in the 
hereinbefore referenced U.S. patent application, and for supportingly 
carrying those blocks through the various operations subsequent to 
casting. 
The combination die and pallet assembly of the present invention includes a 
rectangular die and pallet plate of solid heavy gage metal with a 
plurality of frustro-conical apertures formed therethrough, with those 
apertures disposed in a predetermined array. The apertures are arranged in 
longitudinal and transverse rows, with the spacing being in accordance 
with the pattern of projections which are to be cast on the blocks. In 
accordance with accepted industry practices, three blocks are cast 
simultaneously, thus, the die and pallet plate is provided with a 
sufficient number of the apertures to simultaneously form the desired 
pattern of projections on three blocks. 
In addition to the die and pallet plate, the combination die and pallet 
assembly of the present invention further includes a solid heavy gage 
metal backing plate which is disposed in contiguous engagement with the 
bottom surface of the die and pallet plate during block casting 
operations, and is separated from the die and pallet plate during 
subsequent block handling operations. 
The solid heavy gage metal die and pallet plate is inherently a 
dimensionally stable precision structure which resists damage, rust out 
and the like, and is easy to repair and otherwise maintain. In addition to 
the above described inherent advantages of the solid heavy gage die and 
pallet plate, some other unexpected advantages appeared during development 
and testing of the structure of the present invention. 
Since the apertures are formed through the heavy gage metal plate, such as 
by drilling, rather than being depressions stamped in sheet metal as is 
the case in the prior art structures, the apertures themselves have sharp 
edges rather than the radiused edges of the prior art depressions. The 
sharp edges of the apertures result in sharp edges being cast on the 
blocks, and this in turn results in an improved interlocking fit between 
the layed blocks. Also, since the apertures passed through the plate, the 
problems of deformed or otherwise damaged projections resulting from dried 
cement particles, foreign matter and the like, collecting in the prior art 
depressions has been eliminated, and the chances of air entrapment has 
been substantially reduced. Another benefit derived from the apertures 
being formed through the solid heavy gage metal die and pallet plate, is 
the improved curing characteristics of the block resulting from direct 
exposure of the cast projections to the heat of the kiln. 
Accordingly, it is an object of the present invention to provide a new and 
improved combination die and pallet assembly for casting and subsequent 
handling of mortarless interlocking cementitious blocks. 
Another object of the present invention is to provide a new and improved 
combination die and pallet assembly for casting and subsequent handling of 
mortarless interlocking cementitous blocks with the assembly being 
inexpensive to manufacture and simple to use. 
Another object of the present invention is to provide a new and improved 
combination die and pallet assembly for casting and subsequent handling of 
mortarless interlocking cementitious blocks, with the assembly being a 
dimensionally stable and precision structure, which is of sufficient 
strength to resist damage. 
Another object of the present invention is to provide a new and improved 
combination die and pallet assembly for casting and subsequent handling of 
mortarless interlocking cementitious blocks, with the assembly being easy 
to repair in the event of damage, will resist rust out, and will 
facilitate cleaning and other maintenance. 
Another object of the present invention is to provide a new and improved 
combination die and pallet assembly for casting and subsequent handling of 
mortarless interlocking cementitous blocks, with the assembly forming 
sharp edged, frustro-conical projections on the blocks being cast thereon. 
Another object of the present invention is to provide a new and improved 
combination die and pallet assembly for casting and subsequent handling of 
mortarless interlocking cementitious blocks, with the assembly including a 
solid heavy gage metal die and pallet plate having a predetermined array 
of frustro-conical apertures formed therethrough, and a solid heavy gage 
metal backing plate which is removably disposed in contiguous engagement 
with the bottom surface of the die and pallet plate. 
Still another object of the present invention is to provide a new and 
improved combination die and pallet assembly of the above described 
character which improves the cast integrity of the blocks, and enhances 
the curing characteristics thereof. 
The foregoing and other objects of the present invention, as well as the 
invention itself, may be more fully understood from the following 
description when read in conjunction with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring more particularly to the drawings, FIG. 1 illustrates the 
combination die and pallet assembly of the present invention which is 
shown as including a die and pallet plate, that is indicated generally by 
the reference numeral 10, and a backing plate that is indicated generally 
by the reference numeral 12. 
Before entering into a detailed description of the die and pallet plate 10, 
and the backing plate 12, a brief description of the type of mortarless 
interlocking cementitious blocks cast thereon is deemed advisable. 
The block, which is indicated in its entirety by the reference numeral 14, 
is seen to be of conventional rectangular configuration with a spaced pair 
of vertically extending passages 15 and 16 formed therethrough. The blocks 
14 are cast with eight male frustro-conical projections 18 which depend 
from a horizontal surface 19 which is the bottom surface during casting 
operations and becomes the top surface when a plurality of such blocks are 
employed in construction jobs. 
The projections 18 are arranged in the horizontal surface 19 of the block 
14 in two spaced longitudinally extending rows with four projections in 
each row. The four projections at one end of the block define a perfect 
square, the four projections at the other end of the block form an 
identical perfect square, and the four intermediate, or centrally located, 
projections also form a perfect square which is identical to the end 
surfaces. Although not shown, the upper horizontal surface of the block 14 
is provided with a plurality of frustro-conical recesses, or the 
equivalent formed therein with those recesses arranged in an array which 
is identical to the above described array of the male projections 18. The 
male projections 18 and the female recesses (not shown), are complimental 
block interlocking elements, and due to the particular patterns of these 
projections and recesses, the blocks can be interlockingly assembled in 
the various dispositions commonly used in the construction industry. 
It has long been the practice of the block industry to employ block making 
machines which are adapted to simultaneously cast three blocks in each 
cycle of the machine. Therefore, the combination die and pallet assembly 
of the present invention is preferably configured in conformity with this 
accepted practice. It will be understood however, that the combination die 
and pallet assembly of the present invention may be configured to 
accommodate more or less blocks if desired. 
As shown, the die and pallet plate 10 is a rectangular planar structure 
defined by an opposed pair of spaced apart longitudinal side edges 22 and 
23 and an opposed pair of spaced apart end edges 24 and 25. The die and 
pallet plate 10 is provided with a plurality of frustro-conical apertures 
28 formed therethrough with the apertures arranged in four longitudinally 
extending rows 30a, 30b, 30c and 30d, and six transversely disposed rows 
32a, 32b, 32c, 32d, 32e and 32f. As seen in FIG. 1, the cementitious 
blocks 14 (one shown) are disposed atop the plate 10 so that the 
longitudinal dimensions of the blocks are transverse with respect to the 
longitudinal dimensions of the plate. In this manner, two of the 
transverse rows 32a-32f are located below each of the blocks during the 
casting operations. For example, the transverse rows 32e and 32f are 
disposed below the block 14, and the spacing of the apertures 28 in their 
respective transverse and longitudinally rows is such that the male 
projections 18 of the block 14 will be cast in the precise array as 
hereinbefore described. 
The die and pallet plate 10 is fabricated of solid heavy gage metal such as 
a suitable steel which has the properties necessary to resist denting, 
bending, or other damage which may and sometimes does occur as a result of 
usage. 
With regard to the dimensions of the die and pallet plate 10 the length and 
width thereof are determined by the dimensions of the blocks and the 
number of blocks cast thereon. For example, the block 14 will typically be 
16 inches in length, thus the width of the die and pallet plate 10 will be 
approximately 20 inches and the width of the block 14 is eight inches so 
that the length of the die and pallet plate 10 will be approximately 30 
inches to accommodate three of the blocks 14 in side by side relationship. 
With regard to the thickness dimension, the die and pallet plate 10 is 
preferrably three-eights of an inch thick, but plates of one-quarter inch 
or of one-half inch can be used. 
As seen best in FIG. 2, each of the frustro-conical apertures 28 are formed 
in the plate 10 so as to be inverted, i.e., the larger hole is in the 
upwardly facing surface. The apertures 28 which are formed such as by 
drilling, will be seen to have sharp edges 34 and 36 which results in the 
projections 18 being cast on the blocks without a radius at those 
locations. These sharp edges on the projections 18 result in improved 
interlocking fits between the plurality of blocks which are interlockingly 
assembled to form buildings, retaining walls, and the like. 
The backing plate 12 is also of heavy gage metal, preferrably at least 
one-quarter of an inch thick and having length and width dimensions which 
substantially match that of the die and pallet plate 10. 
In use, the die and pallet plate 10 is placed atop the backing plate 12, as 
seen best in FIG. 2, so that the backing plate is in contiguous engagement 
with the bottom surface of the die and pallet plate. In this manner, the 
apertures 28 formed through the die and pallet plate 10 are closed at 
their bottoms by the backing plate 12. When the blocks 14 (one shown) are 
cast in accordance with the well known and commonly employed techniques, 
the cement will flow into the apertures 28 and the blocks will be 
integrally cast with the male frustro-conical projections 18 thereon as 
hereinbefore described. When the casting operation is completed, the 
combination die and pallet plate assembly will support three of the blocks 
14 thereon, with those blocks being in the uncured or green state. The die 
and pallet plate 10 is then moved off of the backing plate 12, and the die 
and pallet plate 10 having the blocks thereon is thereafter employed as a 
pallet which is transferred to the kiln (not shown). In actual practice, 
the separation of the die and pallet plate 10 from the backing plate 12 
may be accomplished in any convenient manner with the preferred method 
being to fixedly attach, such as with bolts (not shown), the backing plate 
12 to that portion of the block making machine (not shown) which raises 
and lowers the combination die and pallet assembly during each cycle of 
the machine. In this manner, a conventional conveyor system (not shown) 
can deliver and remove the die and pallet plates 10 in the usual manner. 
Such removal of the die and pallet plate 10 from the backing plate 12 with 
the green blocks thereon will result in the male projections 18 of the 
blocks 14 having perfectly formed flat bottom surfaces due to the sliding 
movement of the die and pallet plate 10 off the backing plate 12. This 
removal also enhances curing of the green blocks in that the projections 
18 of the blocks 14 will be directly exposed to the heat of the kiln (not 
shown) through the open bottoms of the apertures 28. 
While the principles of the invention have now been made clear in an 
illustrated embodiment, there will be immediately obvious to those skilled 
in the art, many modifications of structure, arrangements, proportions, 
the elements, materials, and components used in the practice of the 
invention, and otherwise, which are particularly adapted for specific 
environments and operation requirements without departing from those 
principles. The appended claims are therefore intended to cover and 
embrace any such modifications within the limits only of the true spirit 
and scope of the invention.