PROVIDIONAL Tapering or Thinning of Colliery Pit Wooden Props to Prevent Breakage when used in Mines.
Year: 1899

page_text: Date of Application, 11th May, 1899
OLL
1100 Monnoted 12th lon
1000
Date of Application, 11th May, 1899
Complete Specification Left, Oth Dec., 1109 Accepted, 1
13th Jan 1000..
PROVIDIONAL
Tapering or Thinning of Colliery Pit Wooden Props to Prevent
Breakage when used in Mines.
WILLIAM HUTTON HEPPLEWHITE, H.M. Inspector of Mines, Blenheim Mount,
St. Ann's Hill, Nottingham, do hereby declare the nature of this invention to
be as follows:-
The invention consists of, in tapering or thinning of one or both ends of
colliery pit wooden props a stipulated distance, that are used in supporting the
superincumbent strata (known as the roof) after extracting the coal or other
mineral.
The distance of tapering or thinning to be determined by the length of prop
used, the minimum not to be less than 9 inches and the maximum not to exceed
18 inches. The thinnest point of the tapering not to be less than half the
thickness of prop used. The tapering or thinning of props can be any shape
the complete round will be found the best, and can be done by manual labour,
machinery, or any other method.
."
Instead of breaking, often in the middle, kneeing, or buckling, as is the-case
with the present form of colliery pit props, especially the case where the floor
of the mine is excessively hard, and impenetrable, the tapered end will simply
become fuzzy, or a turning up of the wood from the bottom upwards, according
to the amount of weight of the superincumbent strata and length of time allowed
to remain in the back waste, or other places.
The prop so treated will be saved from breakage, and after the fuzzy or
turned up portion has been removed it will be ready to reset in a suitable place.
It is claimed that the workmen will be more secure in their working places,
because nearly every prop will be erect and practically as sound as when first set.
It will save the workmen from having to replace broken props, and a saving
to the owners of having to supply two or more props where one will suffice.
Dated this 6th May 1899.
1
Tapering or Thinning of Colliery Pit Wooden Props to Prevent
Breakage when used in Mines,
I, WILLIAM HUTTON HEPPLEWHITE, of Blenheim Mount, St. Ann's Hill,
Nottingham, one of Her Majesty's Inspectors of Mines, do hereby declare the

page_text: 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:-
My invention consists of the tapering or thinning of one or both ends of
colliery or pit wooden props and bars, as used in collieries, mines, and the like
for supporting the superincumbent strata (known as the roof and sides of the
mine) after the seam of coal or other minerals have been extracted.
The amount or extent to which one or both ends of the props or bars are
tapered is determined by the length of the prop and the normal depression of
the roof; but I prefer that the minimum should not be less than one inch,
and the maximum should not exceed thirty-six inches of the length; and that
the thinnest point of the tapering should not be less than one inch.
This tapering of the props and bars can be either on one or more sides of the
prop and of any desired form; but I prefer that they be tapered uniformly all
round at one or both ends by hand, machinery, or other suitable means.
When the props or bars are thus treated, instead of breaking, buckling or
shearing, as is the case with the present form of props, the tapered end or ends
of the props will simply become fuzzy and turn up at the ends by reason of the
superincumbent weight of the strata; and the props or bars will thus be saved
from breakage by reason of the ends being reduced in area so as to become
relatively weaker than the other portion of the props. When the weight of
the strata has burred or turned up the ends of the props, it is only necessary to
cut off the damaged ends and again taper same, and by this means the whole
length of the props is saved from breakage, as now occurs with untapered props
and bars.
In order that my said invention may be more clearly understood and more
readily carried out and into effect, have annexed herewith a sheet of drawings,
-whereon, the same letters of reference refer to similar parts throughout the
several figures--and whereon the props are shown tapered as described.
Figure 1 represents a prop or bar tapered at one end according to my invention.
Figure 2 represents a prop or bar tapered at both ends according to my
invention.
Figure 3 represents a prop or bar as now commonly used with untapered ends.
In these figures A is the prop or bar and B, B₁ show the ends tapered as
described above to any required degree and shape.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
In pit props or bars as used in collieries, mines and the like, tapering one or
both ends of these props or bars, for the purposes named and substantially as
hereintofore described and shown on the accompanying drawings.
Dated this 5th day of December 1899.
H. WALKER HILL,
2, Church Gate, Nottingham, Agent for the Applicant.