AN IMPROVEMENT OR IMPROVEMENTS IN TELESCOPIC GAS HOLDERS
Year: 1855

page_text: LETTERS PATENT to Thomas Piggott, of Birmingham, in the County of
Warwick, Manufacturer, for the Invention of "AN IMPROVEMENT OR
IMPROVEMENTS IN TELESCOPIC GAS HOLDERS."
Sealed the 16th November 1855, and dated the 21st May 1855.
PROVISIONAL SPECIFICATION left by the said Thomas Piggott at the
Office of the Commissioners of Patents, with his Petition, on the 21st
May 1855.
I, THOMAS PIGGOTT, of Birmingham, in the County of Warwick, Manufac-
turer, do hereby declare the nature of the said Invention for "AN IMPROVE-
MENT OR IMPROVEMENTS IN TELESCOPIC GAS HOLDERS" to be as follows:-
My said Invention consists in fixing together the several sliding parts of the
said gas holders by self-acting mechanism, so that when by the filling of the gas
holder the different sliding parts are raised from the tank, the one last raised
shall be fixed to the one preceding it, and on the sinking of the said gas
holder the several parts shall be detached from one another in an order the
inverse of that in which they were fastened together, and be again capable of
sliding in one another. In carrying my Invention into effect, 1 place a bolt on
the top of the edge of the outer sliding portion of the gas holder, the said bolt
sliding horizontally, and in the direction of a radius of the gas holder; the
outer end of the said bolt carries a friction roller. On the edge of the tank in
which the gas holder sinks is a plane, inclining inwards, against which as the
gas holder rises the outer end of the bolt bears; the said bolt is thereby forced
inwards, and enters a recess in, or otherwise engages with, the inner portion of
the gas holder; by this means the inner and outer sliding portions of the gas

page_text: holder are bolted together, and remain so until the gas holder sinks to nearly
the position at which the inner portion begins to slide within the outer portion,
when the bolt is withdrawn in the following manner :-The part of the gas
holder carrying the bolt carries also a wedge, sliding vertically and engaging
bebind the roller of the bolt. When the gas holder has descended to the proper
distance, a stop fixed on the inside of the tank arrests the said sliding wedge,
and causes it, as the gas holder descends, to wedge behind the roller of the bolt
and withdraw the said bolt. I have only described one bolt, but any suitable
number (according to the size of the gas holder) may be used; and although I
prefer in the bolt the sliding action which I have described, yet the said bolt
may turn upon a joint, and act as well or nearly as well as the sliding bolt.
But this and other modifications of my said Invention I do not consider it
necessary here to describe.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Piggott in the Great Seal Patent Office on the
16th November 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
PIGGOTT, of Birmingham, in the County of Warwick, Manufacturer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of May, in the year of our Lord One
thousand eight hundred and fifty-five, in the eighteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Piggott, Her special licence that I, the said Thomas Piggott, my
executors, administrators, and assigns, or such others as I, the said Thomas
Piggott, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVEMENT OR IMPROVE-
MENTS IN TELESCOPIC GAS HOLDERS," upon the condition (amongst others) that
I, the said Thomas Piggott, by an instrument in writing under my hand
and seal, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Thomas Piggott, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof (that is to say) :-
My said Invention consists in fixing or locking together the several sliding
parts of telescopic gas holders by self-acting mechanism, as herein explained,
the said mechanism so acting, that when by the filling of the gas holder the
part last raised shall be fixed to the one raised next before it, and on the sinking
of the said gas holder the several parts shall be detached from one another, in
an order the inverse of that in which they were fastened together, and the said
parts be again capable of sliding into one another.
Figure 1 represents in elevation (partly in section) one method of carrying my
Invention into effect. I place a bolt a on the top of the outer sliding portion
b of the gas holder, the said bolt sliding horizontally in the case c, fixed to the
outer part of the gas holder b. The said bolt has motion in the direction of a
radius of the gas holder. The outer end of the bolt a carries an antifriction
roller d. is the edge of the tank in which the gus holder sinks. On the said
edge e is fixed the vertical inclined plane f; to the lower part of the incline f
is affixed a stop or projection g. h is a wedge, the lower end of which slides
in the guide i, and the upper end passes through a slot in the bolt a.
When the several parts are in the positions represented in the Drawing, the
inner end of the bolt a enters a staple or recess k in the inner sliding part!
of the gas holder, and fixes the said inner part 7 and outer part 6 of the gas
holder together, and the said parts remain locked or bolted together until the
lower edge of the part 6 of the gas holder has approached to within a short
distance of the bottom of the tank. When by the descent of the gas holder
the bolt a has arrived at the level, represented in dotted lines, the said bolt a
will have been withdrawn from the staple ; for the wedge h being prevented
from descending by the stop 9, the inclined stationary edge of the said wedge
acting against the roller of the descending bolt, causes the said bolt to move
horizontally from the position represented to that indicated in dotted lines
The inner part being now completely detached from the outer part b, the
said part may descend freely in the said part b. When the inner part ↳
risesfrom the position indicated in dotted lines it carries up the outer part b,,
and the roller of the bolt (in the position indicated by dotted lines) coming
against the incline f is forced inwards, and when the gas holder has risen:
to the position represented, the bolt a has become engaged in the staple or
recess k
The wedge h remains stationary during the rising of the bolt a from
the position indicated in dotted lines to that represented in continuous lines.

page_text: Figure represents in elevation (partly in section) another method of
carrying my Invention into effect. m is the inner and the outer sliding
portions of the gas holder; o is a rack on the part m, and p a pinion turning
on the top of the part ; q is a ratchet wheel on the pinion p; is a pall or
click which engages in the ratchet wheel q; s is an arm or lever connected
with the pall . As the part m rises from the position indicated in dotted
lines, the rack o engages with and carries round the pinion p in the direction
indicated by the arrow, until the part n begins to rise, when the two parts
m, n, become locked together. The part m is incapable of rising higher
without the part n, and the part m is incapable of descending within the part
n, for the click r prevents the rotation of the ratchet wheel q and pinion p in
the direction contrary to that indicated by the arrow. During the ascent of
the gas holder the parts m, n, are consequently so locked or engaged together
as to be incapable of moving without one another. When, however, the
gas holder has descended until the bottom edge of the part n has nearly come
to rest on the bottom of the tank, the arm s, coming in contact with the stop t,
assumes the position indicated in dotted lines, and the click r becomes disen-
gaged from the ratchet wheel g; the pinion p has now liberty of motion, and
the parts m, n, are unlocked or disengaged from one another.
As
When the
parts u, v,
Figure 3 represents in elevation (partly in section) another method of
carrying my Invention into effect. is the inner and the outer parts of the
gas holder; w is a rack on the part u; a is a pall or click on the part v.
the part u ascends, the rack w escapes under the pall or click a
part u has risen so high as to commence lifting the part v, the two
are fixed or locked together. y is a pin connected with the pall or click æ,
which said pin engages in the slot in the disc 1. When the gas holder has
descended until the disc 1 assumes the position indicated in dotted lines, the
arm 2 having been arrested by the fixed stop 3, a partial rotation has been
effected in the disc 1, and the pall or click has been withdrawn from the
rack w, as will be understood by reference to the parts in dotted lines. The
part w, being now disengaged from the part , can readily slide therein.
Figure 4 represents in elevation, partly in section, another method of
carrying my Invention into effect. 4 is the inner and 5 the outer parts of the
gas holder; G is an arm or lever turning upon the part 4; a spring 7
pressing upon the short arm of the lever, tends to keep it in the position
represented. When the arm 6 is in the position represented, its lower end
bearing on the top of the part 5, the two parts 4 and 5 are locked together.
On the descent of the gas holder the arın 8 comes in contact with the stop 9,
and gives motion to the pinions 10, 11, in the directions indicated by the

page_text: arrows. A tooth 12 on the pinion 11 engaging in the bolt 18 pushes the lever
6 into a nearly vertical position, as indicated by dotted lines, when the said
lever 6 no longer bears upon the top of the part 5, when the part 4 may slide
freely within the part 5. When the part 4 rises, the lever 6 resumes the
position represented in the Drawing, the bolt 13 no longer pressing the said
lever 6 inwards.
Figure 5 represents in elevation, partly in section, another method of
carrying my Invention into effect. 14 is the inner and 15 the outer parts of
the gas holder; 16 is a bolt sliding horizontally on the top of the part 15;
17 is a lever, the short angular arm 18 of which engages in the bolt 16; 19 is
a weight hung on the end of the arm 17 by means of a slot in the weight.
When the gas holder descends, the weight 19 comes in contact with the top 20
of the tank; a spring acting on the rod 21 presses the lever 17 upwards, so as
to keep it to its bearing in the slot in the weight 19; the lever 17 thereby
virtually rises as the gas holder descends, and the short arm 18 withdraws the
bolt 16 from the staple or recess on the part 14, in which it had been engaged.
The bolts or locking mechanism described and represented may be placed
round the gas holder at equidistant points in any desired number.
Having now described the nature of my said Invention, and the manner of
carrying the same into effect, I wish it to be understood that I do not limit
myself to the details herein described and represented, as the same may be
varied without departing from the nature of my said Invention; but I claim
as my Invention, locking together and unlocking the separate parts or lifts of
telescopic gas holders, the said locking being effected on each of the said parts
or lifts as the same is about to be raised from the tank, and effecting its fixed
connection with the part which had previously been raised, and the said
unlocking being effected in an inverse order to that of the locking; the
said locking and unlocking being effected by mechanism brought into action
by the motion of the gas holder.
In witness whereof, I, the said Thomas Piggott, have hereunto set my
hand and seal, this Eighth day of November, in the year of our Lord
One thousand eight hundred and fifty-five.
Witness,
GEORGE SHAW.
THOMAS PIGGOTT. (L.S.)