Improvements in Paving Blocks.
Year: 1894

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by GUSTAF BAGGE, of Antony (Seine), in the
Republic of France, late Captain of the Guards of the King of Sweden.]
Improvements in Paving Blocks.
I, HENRY HARINGTON LEIGH, Assoc. M. Inst. C.E., Fel. Ch. Inst. P.A.,
F.I. Inst., practising as Phillips and Leigh at No. 22 Southampton Buildings,
Chancery Lane London, W.C., Engineer and Chartered Patent Agent, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
This invention relates to improvements in paving blocks.
A considerable variety of materials, natural or composite, have been successively
tried for paving the streets of large towns. But, in spite of the degree of success
achieved for some of such materials, they left everything to be desired. Pavements
in blocks are too hard for horses' hoofs, they sink unequally into the ground and
the wheel traffic over them is too noisy. Macadam is very expensive to keep in
repair and too muddy in wet weather. Asphalte and wood paving are likewise
very expensive, wear out quickly and are very slippery when it is wet. Further,
asphalte varies a great deal in respect of its consistence according to the
temperature. It becomes soft during very hot weather. Gangs of skilled workmen
and supplies of gravel along the thoroughfares are necessary to keep the roadways
gravelled as soon as it begins to rain. The inventor cites only the above four
types of pavement which are the only types which have become acclimatised in
large towns with their enormous and varied wheeled traffic.
The improved composition which constitutes the present invention anticipates all
the known drawbacks in paving materials by possessing the good qualities of some
and being without the defects of others. In principle, it is a pavement of wood
and stone combined.
In carrying the invention into effect, I mix sawdust with stones broken small and
add thereto a suitable binding agent if there is reason for so doing. The stone
should be granite, or at least, equally hard. When the sawdust is resinous, the
natural resin will be there in sufficient quantity to, under the combined influence of
heat and great pressure, hydraulic or otherwise, bind the small broken stones
together. Otherwise, there is added to the mixture, either resin or albumen or
other material adapted to act as a binding agent under the said combined influence
of heat and great pressure.
When the mixture is finished according to the process
of agglomeration explained above, it is introduced into hot moulds having the
desired contour of the paving block and subjected to heavy pressure in a hydraulic
or other press. The application of heat is maintained during the compression
according to the nature of the binding agent.
The paving blocks produced by the said process possess the properties of wood
blocks, because there is so much wood in them, but it possesses them in a better
way than do the sawn blocks, because the former are free from the inequalities in
respect of hardness which are inherent in natural wood. Subjected to an enormous
pressure and always uniform, the wood portions of the said paving 'blocks possess
uniform powers of resistance. At the same time, the wear comes upon the small
stone embedded in the blocks, and as these offer a greater resistance to said wear
than the sawdust, the desired degree of roughness necessary to prevent horses
slipping in wet weather is secured to the roadway.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
A new composition for paring blocks consisting of a mixture of sawdust and
stones broken small cemented together by means of a binding agent under the
simultaneous influences of pressure and heat.
Dated this 22nd day of January 1894.
HENRY H. LEIGH.