Split-slab house construction

A house includes a split-slab foundation having an upper portion constructed within an enclosed on-tract factory and a lower portion constructed on the lot. The superstructure of the house is erected upon the upper portion, and the super-structure and upper portion are transported off-highway by air-cushion transport to the lot where the slab upper portion is mated with the lower portion. The upper portion is uniquely constructed with areas of increased thickness to withstand the shear forces of parts of the house having substantial weight, with pipe passageways to accommodate pipes built into the lower portion, and with means for releaseably attaching an air impermeable skirt used for air cushion transport. The lower portion is uniquely constructed with recessed areas to accommodate the areas of the upper portion having increased thickness and the pipes therein are positioned to be in register with the passageways in the upper portion. Both the upper and lower portions are provided with means for securing the upper portion to the lower portion.

FIELD OF THE INVENTION 
The present invention relates generally to a form of house construction and 
more particularly to a procedure for single-builder development of a large 
tract of land by mass producing houses of such construction at a plant, 
preferably within an enclosed factory and then transporting the completed 
houses by air cushion to their ultimate site. 
DESCRIPTION OF THE PRIOR ART 
In an effort to reduce the ever-increasing cost of building houses, members 
of the home construction industry often turn to factory-built homes. For 
present purposes, a home may be considered to be any form of dwelling of 
some degree of permanence such as mobile homes, quonset huts, and 
including also more conventional structures known as houses. Factory 
building of homes using production line procedures within the confines of 
a partially or fully-enclosed structure offers numerous cost-reducing 
advantages over traditional on-site construction. Losses due to 
weather-created delays and damages, vandalism, and theft are substantially 
reduced if not eliminated altogether. Equipment and labor can be 
concentrated in a small area resulting in more efficient allocation of 
such equipment and manpower. Production line techniques allow for simpler, 
more straight-forward methods of construction as well as for delegation of 
specialized duties for laborers. 
In addition to such expense-saving features, the quality of 
factory-constructed homes is better assured. For instance, the homes still 
in process of construction are not exposed to inclement weather conditions 
resulting in accelerated decay and warping of wooden frame. Also, 
production line techniques assure better supervision of construction 
workers and improved quality control. 
Examples of techniques of constructing factory-built homes are shown by 
U.S. Pat. No. 3,571,993, issued to Potter on Mar. 23, 1971; U.S. Pat. No. 
3,796,162, issued to Burdick, et al, on June 28, 1972; and U.S. Pat. No. 
3,757,931, issued to Baker et al., on June 9, 1971. The Burdick and Baker 
references disclose a method of moving mobile homes through an assembly 
line by way of a form of air bearing transport. Potter discloses an 
assembly line prefabricated building structure and means for moving such a 
structure to its ultimate site by way of a crane. Potter further discloses 
advance preparation of the ultimate site by pouring a set of four or more 
concrete piers to which the prefabricated structure is attached. Another 
form of factory constructed home taught by the prior art is the mobile 
home. After being pulled to a lot, a mobile home is generally attached to 
the lot by such means as guy-wires or hurricane straps. In many instances, 
a concrete block foundation is constructed beneath the mobile home and the 
wheels then are removed. 
Acceptance of such factory-built homes has been far from unanimous for 
three reasons. First, such homes are often regarded as unsafe because of 
their light construction and because they are poorly secured to the lot 
itself. High winds often cause severe damage to mobile homes and similar 
modular homes while homes of conventional construction are unscathed. 
Second, lightweight construction, steel beams and trusses detract from 
both the interior and exterior appearance of the home. Most of the 
factory-built homes in the prior art have a box-like appearance with a 
simplified floor plan that does not appeal to most home purchasers. Third, 
factory-built homes do not offer many of the desired features of the 
conventional house including slab foundation, picture windows, sliding 
glass doors, brick exteriors, fireplaces, high-trussed roofs, staircases, 
porches, attached garages, two-story floor plans and basements. 
The foregoing deficiencies arise in large part because many of the prior 
art factory built homes are intended to be transported over public 
highways or on railroads, which imposes design limitations relating to 
weight and shape. 
These problems might be limitedly corrected by onsite finishing of the 
home. Such finishing reintroduces the problems of conventional 
construction that factory construction seeks to eliminate thus defeating 
the advantages of factory-built homes. 
Potter, supra, seeks to solve these problems by means of a special house 
structure. The actual structure described in Potter is substantially 
different from that used in conventional construction thus resulting in a 
home that is different from conventional houses both in appearance and in 
features. Furthermore, a stated purpose of Potter is a house having a 
minimum weight. Such a limitation automatically eliminates such heavy 
structural items as fireplaces, attached garages and brick exteriors. 
Thus, the problem remains of providing a factory-built home that offers the 
safety, appearance and features of the conventional house. A technique is 
required that will allow for transport from factory to site of a completed 
home having any construction, including brittle features such as slab, 
picture window, high-truss roof, sheetrock walls, brick exteriors, 
fireplaces, staircases and the like, e.g. a conventional house. 
SUMMARY OF THE INVENTION 
The present invention is a house having a split-slab foundation, and a 
method of building and transporting such a house whereby it is susceptible 
to mass production in an on-tract enclosed factory structure resulting in 
rapid, economical development of a large tract of land. The split-slab has 
an upper portion upon which a house of any composition and design is 
built. The upper portion is of substantially uniform thickness, but may be 
reinforced by areas of increased thickness at points where the weight of 
the house structure at those points is substantial, such as points upon 
which a brick wall or fireplace is constructed. The lower portion is 
prepared on a home site and has an upper surface designed to mate with the 
lower surface of the upper portion. Thus, recesses in the upper surface of 
the lower portion are provided where the upper portion is reinforced by 
areas of increased thickness. The lower portion is appropriately designed 
to the soil conditions in the area and may include beams and bell-bottom 
piers. The lower portion and upper portion may be correlatively designed 
to accomodate utility connections, especially drainage pipes installed 
through or within the foundation. 
The method involves selecting a multi-lot tract of land, building on the 
tract a factory wherein a plurality of house structures are built to be 
placed on the lots, and building an on-tract enclosed factory, 
constructing the major portion of each house within the enclosed factory 
by pouring the upper portion of the foundation, allowing it to cure, and 
by means of a production line, constructing the complete house 
superstructure on the upper portion while it remains indoors. When 
construction of the house is completed, the house is towed to the 
home-site by air-cushion transport which is defined herein as attaching a 
flexible, air impermeable skirt to the periphery of the upper portion and 
forcing air beneath the upper portion by a blower such that the air is 
trapped within the confines of the skirt and beneath the slab. The upper 
portion of the house, together with the house super-structure constructed 
thereon, is thus lifted upon an air-cushion allowing it to be pulled along 
the ground by tractor or other means. Although the house may be extremely 
brittle, the house may be towed over the tract which may be rough, 
unprepared terrain or new streets not yet in general use. At the 
home-site, the air-cushion supported house is placed over a prepared lower 
portion adapted to receive the upper portion and the house is lowered 
until the upper portion meshes with and rests upon the lower portion. 
By virtue of the present invention, a home of any construction, especially 
of conventional house construction, may be factory-assembled and installed 
on a house-site. The only on-site construction involved is preparation of 
a portion of the foundation and connection of utilities, such as gas, 
water, power and sewage. Also, factory construction of upper portion of 
the foundation and the house superstructure need not vary from one 
geographical region to another. Only construction of the lower portion of 
the foundation must be varied according to soil conditions. 
The method of the invention can be used to develop a large tract of land by 
subdividing the tract, erecting the enclosed plant, constructing the upper 
portion of the foundations and house superstructures within the plant, 
transporting them to and mating them with their respective lots, 
disassembling the plant and moving the equipment to a second tract of land 
to be developed. 
Air-transport of large, heavy objects across rough terrain is not claimed 
generally as the invention. Such apparatus and methods are described in 
the prior art by such publications as U.S. Pat. No. 3,693,729 issued to 
Blurton, et al., on Sept. 26, 1972 (transport of oil well drilling rig); 
U.S. Pat. No. 3,840,089 issued to Allison on Oct. 8, 1974 (modular 
air-cushion platform); U.S. Pat. No. 3,520,381 issued to Pinder on July 
14, 1970 (transport of storage tank); and U.S. Pat. No. Re. 28,101 issued 
to Knorr on Aug. 6, 1974 (transport of oil well drilling rig). These 
references, however, do not disclose use of the air-cushion technique with 
a structure having an irregular shape which may result in internal corners 
nor do they disclose that such a technique will work for brittle objects. 
Furthermore, the air-cushion transport disclosed by these references does 
not teach mating an upper portion of a foundation with a lower portion of 
the foundation or running utility connections, including plumbing, through 
the floated object, nor the development of a tract by building a factory 
thereon and air transporting a house structure off-highway to a lot on the 
tract. 
Nor is air transport of houses broadly claimed as invention. U.S. Pat. No. 
3,796,162 issued to Burdick, et al, on June 28, 1972, and U.S. Pat. No. 
3,757,931 issued to Baker, et al., on June 9, 1971 teach use of air 
bearings in transporting houses along assembly lines. The air-bearing 
methods disclosed in Burdick and Baker, however, as distinguished from 
air-cushion transport, are not suited for transporting a house from the 
factory to the mating site for several reasons. First, the air-bearing 
methods require a smooth, level path of transport thus negating use on 
rough terrain. Second, the height to which th object can be elevated above 
the ground is very small. Thus, the object cannot be guided over utility 
connections installed in the mating site. Third, because the "lift" of the 
air bearing occurs over a small surface area, the air pressure required to 
lift an entire conventionally built house is very high and, essentially, 
prohibitive. Fourth, the air bearing methods use a platform on which the 
house rests thus requiring the additional steps of either removing the 
platform or removing the house from the platform prior to mating with the 
site. Finally, Burdick and Baker involve the use of rails which are not 
feasible for transporting a house from factory to ultimate site. 
Comparatively, air-cushion transport may be used over rough terrain, on 
inclines and declines, may be used to lift a house to heights of several 
feet, requires air-pressure in the order of only two pounds per square 
inch, and requires no rails.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The method of building houses taught by the present invention and 
illustrated in FIGS. 1 through 10, and 15 of the drawings includes 
building an enclosed factory on a tract of land to be developed, surveying 
the tract to divide it up into housesites, preparing the housesites, and 
the steps performed within the enclosed factory of pouring the upper 
portion 11 of a concrete slab foundation 13 and erecting a house 
superstructure 15 upon the upper portion, and outside the enclosed factory 
preparing a mating site which includes the lower portion 17 of the 
foundation 13, transporting the upper portion 11 with house superstructure 
15 thereon from the enclosed factory to the mating site by means of 
air-cushion transport, and mating the upper portion 11 to the lower 
portion 17. 
In performing the method of the invention in the preferred manner, the 
enclosed factory or plant is erected upon a tract of land to be developed 
as medium density residential property. The plant should be large enough 
to house several houses at a single time as well as house supplies and 
equipment used to construct such houses. The plant should have doors large 
enough to allow a completed house of substantial size to move through 
them. The nature and design of the plant or factory itself should be such 
that it can be quickly disassembled and later re-erected central to a 
second tract of land to be developed. 
After the plant is erected, construction of the upper portion and lower 
portion of the foundation is commenced simultaneously within the enclosed 
structure and at the mating site, respectively. Upper portion 11 is formed 
within mold 101. As shown in FIG. 1, mold 101, having base 103, side walls 
109, offsets 104 and 106 and a plurality of hole molds 108 attached to 
side walls 109, is placed on mobile frame 100 which has supports 110 and 
wheels 102. Frame 100 is large enough to support all of mold 101 with no 
overhang. Both mold 101 and frame 100 are constructed of rigid metal such 
as steel. 
The upper portion of the foundation, as formed in its corresponding mold, 
has a configuration that varies according to the floor plan and general 
nature of the house superstructure to be constructed thereon. Basically, 
upper portion 11, as shown in FIG. 2, and as formed by mold 101 of FIG. 1, 
is a steel-reinforced concrete slab having generally flat upper surface 
21. If house superstructure 15 is to have a brick, brick veneer, adobe 
block, or similar exterior surface, upper surface 21 of upper portion 11 
has perimeter recess 22 extending about its perimeter to accomodate the 
bricks or blocks 23 of exterior wall 24 as shown in FIG. 3. Upper surface 
21 may additionally have interior recesses 25, as seen in FIG. 2, to allow 
for "sunken" rooms. Recesses 22 and 25 are formed as necessary using 
techniques known in the art, such as by using offsets 104 and 106. 
Lower surface 27 of upper portion 11, as shown in FIG. 2 and as formed in 
the mold of FIG. 1, is generally flat and is parallel to upper surface 21, 
but has ridges 29 and 31 where reinforcement of the upper portion is 
required because objects of substantial weight, such as brick or block 
wall 24 and fireplace 33, as shown in FIG. 3, will be constructed on upper 
portion 11. Ridges 29 and 31 are located directly beneath the 
corresponding objects of substantial weight and extend beyond the area of 
contact between the objects and upper surface 21. Thus, as shown in detail 
in FIG. 8, ridge 31 corresponding to fireplace 33 is located directly 
beneath fireplace 33 as seen by dotted lines 35 and 37 and has a width W 
which extends beyond depth D of fireplace 33 by a distance X in either 
direction. By extending beyond the area of contact by a distance X, ridge 
31 reinforces not only against increased weight of fireplace 33, but also 
against the shear force created along lines 35 and 37 by the difference in 
downward force on either side of each of lines 35 and 37. Similarly, as 
shown in detail in FIG. 9, ridge 29 has a width Y that extends beyond 
thickness T of wall 24 by a distance Z. Base 103 of mold 101 has recessed 
areas 105 and 107 which result in formation of ridges 29 and 31. 
As seen in FIG. 2, upper portion 11 further has a plurality of drainage 
pipe passageways 39 extending therethrough. Each drainage pipe passageway 
39 is perpendicular to the plane of upper surface 21. Passageways 39 are 
designed to accomodate the drainage pipes which will connect to the 
plumbing fixtures in house superstructure 15. Passageways 39 are generally 
cylindrical and have a cross-sectional area corresponding closely to the 
cross-sectional area of the pipe to be accomodated. Location of 
passageways 39 will vary according to the floor plan of house 15 and the 
location of the plumbing fixtures therein. Passageways 39 are constructed 
by inserting passageway molds 112 into mold 101 as seen in FIG. 1. 
Perimeter edge 40 of upper portion 11, as shown in FIG. 2 and as formed in 
mold 101 of FIG. 1, has a plurality of skirt attachment holes 42 formed 
therein by hole molds 108 attached to side walls 109 of mold 101. Skirt 
attachment holes 42 are cylindrical in shape and have axes perpendicular 
to the corresponding perimeter edge 40. As shown in detail in FIG. 5, 
perimeter edge 40 also has upper edge recess 48 at the junction of lower 
surface 27 and perimeter edge 40. 
When mold 101 is properly constructed to form desired configuration of 
upper portion 11, steel reinforcing rods 114 are positioned within mold 
101 and concrete is poured. When concrete of upper portion 11 has cured 
sufficiently within mold 101, side walls 109 of mold 101 are removed. 
Utility passageway molds 112 are removed leaving utility passageways 39. 
House superstructure 15 is then erected upon upper portion 11. 
Construction of the house superstructure may include erection of any kind 
of wall, including gypsum board, wood panel, ceramic material, and brick, 
separating the rooms. The ceiling may be of any construction, including 
gypsum board and tile. The roof may have a high peak or it may be flat; 
numerous gables can be included. The roof may be covered with any surface 
covering. Sliding glass doors, Florida rooms, screened porches, attached 
garages, built-in appliances, fireplaces, picture and bay windows and 
stairways may be included. Floors may be wood, tile, or fully carpeted. 
The exterior might be of any type including, e.g., stone, brick, brick 
veneer, wood frame and adobe brick. The house may have more than one 
story. In-wall pipes, plumbing fixtures, electrical wiring, and light 
fixtures may be included. 
As shown in FIG. 3, house superstructure 15 has utility connections such as 
water pipe 62 and electrical power duct 61 for ultimate connection of 
water supply and electricity (with meter), respectively. In similar 
fashion, superstructure 15 may be provided with natural gas connection. 
Construction of the house superstructure may be accomplished as steps in an 
assembly line by moving upper portion 11 along the floor of the plant 
while mounted in frame 100. Except for final external connection of 
utilities and sewer, every phase of construction of house 15 is completed 
prior to removal of house superstructure 15 and upper portion 11 from the 
interior of the plant. 
When such construction is completed, an internally-threaded skirt anchor 
44, as seen in FIG. 10, is inserted into each skirt attachment hole 42 
until annular collar 46 of skirt anchor 44 rests against perimeter edge 
40. Flexible air-cusion skirt 111, having a plurality of apertures 113 and 
shown in FIGS. 3 and 10 is attached to perimeter edge 40 by aligning each 
aperture 113 over a corresponding skirt attachment hole 42 and threading a 
bolt 73 through each aperture 113 and into a skirt anchor 44. While upper 
portion 11 rests on frame 100, skirt 111 drapes to floor surface of the 
plant. 
As seen in FIG. 3, one end of hose 119 is inserted through air hole 121 in 
skirt 111 and the other end is connected to air blower 123 which is 
mounted on pulling tractor 129. Utility passageways 39 are effectively 
sealed with releasable seal means 126 such as a piece of cloth forced 
within each passageway 39. Air is then blown through hose 119 and air hole 
121 thus creating an air-cushion within skirt 111. The air pressure within 
the skirt under the upper portion of the slab must be sufficient to 
support such upper portion and the house superstructure thereon. For 
example, if the area of the slab is 1000 sq. ft. and the slab and 
superstructure together weigh around 44 tons, a pressure of a little over 
2 psi above atmosphere would be required. As soon as this skirt starts to 
leave the ground, leakage occurs to balance the air pressure and keep the 
slab and house structures from shooting up in the air. The blower capacity 
must be sufficient to produce the desired air pressure despite any leakage 
occurring within its upper part of the skirt and the upper portion of the 
slab. By virtue of this air-cushion, upper portion 11 is lifted from base 
103 of mold 101 and, by means of pulling tractor 129 and guide tractor 
125, moved away from mold 101 and frame 100. Both mold 101 and frame 100 
are then returned to the beginning of the assembly line to be used in 
construction of another house. The house superstructure, supported by 
upper portion 11, and as shown in FIG. 3, is an intermediate step in 
constructing a home. 
Transport of upper portion 11 with house superstructure 15 is along 
completed subdivision streets or along a partially cleared path which may 
include fairly rough terrain and may have both inclines and declines. All 
obstructions exceeding the height of the air cushion are removed from the 
path. 
The lot to which house superstructure 15 is transported is prepared prior 
to transport by clearing the portion of the lot on which the house is to 
sit and constructing a mating site. Construction of the preferred mating 
site shown as lower portion 17 in FIG. 4 is according to methods generally 
known in the art for construction of a reinforced concrete slab foundation 
having pier and beam construction, although a floating slab or other 
suitable form of slab construction can be used. The plan configuration of 
the slab portion 51 of lower portion 17 should correspond to the plan 
configuration of upper portion 11 to be mated to the mating site. 
Construction of lower portion 17 includes erection of the concrete form on 
the lot and arranging steel reinforcing rods and drainage pipes 59 
therein. Drainage pipes 59 run horizontally beneath slab portion 51 from 
sewage connection 64, between piers 54, below beams 52, and through slab 
portion 51 forming vertical pipe ends 41 above slab portion 51. Pipe ends 
41 are to be connected to plumbing fixtures within the house 
superstructure to be mated to the mating site, and, therefore, are 
positioned to correspond to pipe passageways 39 of upper portion 11. 
Location of sewage connection 64 is dependent upon the location of sewers 
in relation to lot 19. 
The concrete form includes offsets whereby the upper surface 53 of slab 
portion 51 can be contoured with recesses 55 and 57 corresponding to 
ridges 29 and 31 of upper portion 11 to be mated with upper surface 53 of 
lower portion 17. Furthermore, the side walls of the concrete form are 
shaped to form lower-edge recess 56 about perimeter edge 50 of slab 
portion 51. (See FIG. 5). 
After lower portion 17 has been constructed and allowed to cure, a thin 
layer of epoxy resin bonding material 66 (See FIG. 5) is spread evenly 
over upper surface 53 of lower portion 17. As shown in FIG. 6, air cushion 
supported house superstructure 15 and upper portion 11 are then aligned 
above lower portion 17 such that pipe passageways 39 are positioned 
directly above pipe ends 41 and perimeter edges 40 and 50 properly 
correspond to one another. With the upper and lower portions thus in 
register, they are telescoped together. To accomplish this the air cusion 
is gradually released and upper portion is lowered while pipe ends 41 move 
into pipe passageways 39 thus forcing seal means 126 from pipe passageways 
39. 
When upper portion 11 is fully lowered onto lower portion 17 such that 
lower surface 27 meshes with upper surface 53 of lower portion 17, skirt 
111 is removed from perimeter edge 40 by removing bolts 73 from skirt 
anchors 44. 
As shown in FIG. 5, after mating of upper portion 11 with lower portion 17, 
mortar 68 is inserted into the groove formed by upper edge and lower edge 
recesses 48 and 56. Mortar 68 can be smoothed by running a trowel about 
the periphery of the completed foundation thus effectively hiding the line 
showing the junction between the upper portion and the lower portion. When 
mortar 68 and bonding material 66 dries, the upper portion is chemically 
bonded to the lower portion. 
At this time, pipe ends 41 are appropriately connected to plumbing 
fixtures. The house is then ready for occupancy. The completed house, as 
shown in FIG. 7, is an example of preferred embodiment of the article of 
manufacture resulting from the inventive method. 
Numerous alternative techniques for performing the steps of the method of 
the invention exist. 
For instance, the house may be fully constructed upon the upper portion of 
the foundation before moving the upper portion within the factory. Entire 
assembly, however, would remain indoors. 
Also, the upper portion of the foundation can be allowed to cure prior to 
being placed on a mobile frame. Upon curing, the upper portion is then 
removed from the mold by crane and placed on a mobile frame. This is 
possible due to the lighter weight of the upper portion prior to 
construction of a house superstructure thereon. 
FIG. 11 shows an alternative method of transporting the upper portion 11 of 
the foundation. Skirt 111 is attached immediately after upper portion 11 
is cured. Thus, upper portion 11 is moved from one stage in construction 
of the house super-structure to another stage by means of air cushion 
transport. When house superstructure is completed, the unit including 
upper portion 11 and house superstructure 15 may be moved immediately to 
the mating site. 
Furthermore, utility connections may be made in a fashion similar to that 
of the drainage pipes 59 and sewer connection 64 by running utility ducts 
beneath and through slab portion 51 of lower portion 17. 
Construction of upper portion and lower portion can result in the 
alternative embodiments of FIGS. 12 and 13. In this embodiment, lower 
portion 217 has no slab portion. Lower portion 217 may be formed by 
clearing the lot to the bedrock, pouring piers in the bedrock, erecting 
beams upon the piers and the bedrock such that the outer beams form a 
periphery having a configuration adapted to receive the upper portion, and 
filling in the spaces within the periphery with sand such that a level 
surface is formed by the beams and sand. Because lower portion 217 has no 
slab portion, upper portion 211 normally is thicker in this alternative 
embodiment than it is in the preferred embodiment. 
Also, construction of the lower portion of the foundation can result in the 
alternative embodiment of FIG. 14 wherein a basement is included. 
Construction of basement slab 301 and basement walls 303 is by techniques 
generally known in the art. Steel reinforced beams 305 support upper 
mating surface 307 of lower portion 309. Utility ducts, shown as pipes 
311, run beneath beams 305 and extend through slab portion 313. The entire 
basement of lower portion 309 is substantially completed prior to mating 
of upper portion. 
The foregoing description relates primarily to the house structure. The 
factory is also an important element of the method. As shown in FIG. 15, 
the factory is preferably located adjacent a highway or railroad spur to 
make it readily accessible to the workman and to make it easy to bring in 
supplies of building materials. The factory should be big enough to allow 
several house structures to be worked on at once as in an assembly line, 
and to provide space for storage of materials and facilities such as 
overhead cranes for handling same. Portable scaffolding, elevated work 
bays and machine tools will be provided. The factory is built on a tract 
that can be subdivided into a large number of lots, for example, a 
thousand, to receive house structures built in the factory and transported 
off-highway (no traffic problem or weight and width limitations) by air 
cushion transport to the desired lots. 
While it has been emphasized that the factory should be enclosed in order 
to provide a controlled environment, the degree of enclosure may of course 
vary. For example there may be certain parts which are totally enclosed 
and others which are merely roofed to protect against the sun or screened 
to protect against insects or animals, or provided with a wall to protect 
from the wind, or merely elevated to protect against high water, or paved 
to protect against ground water, dust, and mud. In any event some form of 
preparation will have been made to constitute a factory suitable for the 
particular requirements of the area where the factory is located and the 
work to be performed. 
The method of the invention and the resulting articles of manufacture have 
been described in detail sufficient to enable one of ordinary skill in the 
art to make and perform the same. Modifications and alterations of the 
preferred embodiments and the preferred methods in addition to those 
described herein and which do not depart from the spirit of the invention 
will occur to others upon a reading and understanding of the specification 
and it is our intention to include all such modifications and alterations 
as part of our invention insofar as they come within the scope of the 
claims.