CERTAIN IMPROVEMENTS IN LOCKS FOR FASTENINGS
Year: 1833

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
PARSONS, of Newport, in the County of Salop, Gentleman, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth;
by His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Third day of December, in the fourth year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
Thomas Parsons, His especial licence, full power, sole privilege and authority,
that I, the said Thomas Parsons, my executors, admors, and assigns, or such
others as I, the said Thomas Parsons, my exors, adñors, or assigns, should
at any time agree with, and no others, from time to time and at all times
during the term of years therein expressed, should and lawfully might make,
use, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, and also in all His said Majesty's Colonies and Plantations
abroad, my Invention of "CERTAIN IMPROVEMENTS IN LOCKS FOR FASTENINGS;"
in which said Letters Patent is contained a proviso that I, the said Thomas
Parsons, shall cause a particular description of the nature of my said Inven-
tion, and in what manner the same is to be performed, to be inrolled in His.
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent, as
in and by the same, reference being thereunto had, will more fully and at
large appear.
NOW KNOW YE, that, in compliance with the said proviso, I, the said
Thomas Parsons, do hereby declare the nature of my said Invention to
consist,―

page_text: Figure 4 is another view of the interior of the lock, the key being in action,
and the bolt ready to be shot. In this view the prop J is shown drawn to the
furthest point from the fulcrum of the lever tumbler C, and the bit of the key
elongated in proportion, as will be more particularly explained hereafter.
Figure 5 is a view of the opposite side of the lock to that shewn at Figures
1 and 4, with the front plate removed in order to show the index X and scale
W. The index. X is attached at Z to the slide f, f, and works through the
slot O, so that by removing the front plate it may be seen exactly how far the
prop J is removed from the fulcrum, and consequently the degree of extension
required' in the bit of the key, in order that it may act correctly upon the lever
tumbler C.
Figure 6 is a similar view to Figure 5, but shows the index at the other
end of the scale.
Figure 7 is the key, a being the adjustable part of the bit.
Figure 8 shows that part of the bit extended.
Figure 9 shows the moveable part of the bit in section, and the collared
adjusting screw which acts upon it separately, there being a female screw in
the neck of the piecé a to receive the screw. The letter t in Figure 8 shows
the pin passing through the side of the stem of the key into the groove made
by the collar on the screw, and which causes the screw when turned to push
out or draw in the part a at pleasure.
Figure 10 is a back view of the key, showing the head of the screw. And
it is only necessary further to add, that I make each degree of the scale W to
correspond with one turn or more, or some fixed portion of one turn of
this screw.
Figure 11 is a padlock, shewing the manner in which I apply two or more
of the lever tumblers aforesaid to act as a bolt for that kind of fastening. This
Figure shows the tumblers C in the position they assume when freely acted.
upon by the springs P, and the shackle therefore fast, and Figure 12 shows
the tumblers (C) correctly raised by the key and the shakle at liberty. If
either tumbler were raised too much or too little, it is evident the shakle
would be prevented from being withdrawn by the tumbler, and consequently it
would remain locked, any inaccuracy in the action of the key on the tumblers
having the same effect on the shakle as it is well known to have when the
tumblers are applied to a bolt.
Figure 13 is the key required for the two tumblers shown in the Drawing.
Now whereas it is evident that my Invention as regards the prop is
susceptible of many modifications, and would apply equally as well between
two tumblers working vertically as it does between one lever and one vertical

page_text: tumbler, provided one or both of their respective edges acted upon by the
prop be inclined planes; and whereas the prop itself might be made to act as
a lever; and whereas the lever tumblers herein-before described as applied to
padlocks are equally applicable to box locks; but whereas I claim as my
Invention,―
First, a moveable or adjustable prop placed as aforesaid, for the purposes
aforesaid, and the slide ff, and screw g as connected therewith..
Secondly, the adjustable part a of the bit of the key with its adjusting
screw, and its reference to the index and scale X, W. And,
Lastly, the manner herein-before described of applying the aforesaid lever
tumblers to act as a bolt to padlocks and box locks.
And such my Invention being, to the best of my knowledge and belief, entirely
new, and never before used within that part of His said Majesty's United
Kingdom of Great Britain and Ireland called England, His said Dominion
of Wales, or Town of Berwick-upon-Tweed, or in any of His said Majesty's
Colonies and Plantations abroad, I do hereby declare this to be my Specifica-
tion of the same, and that I do verily believe this my said Specification doth
comply in all respects, fully and without reserve or disguise, with the proviso
in the said herein-before in part recited Letters Patent contained, wherefore:
I do hereby claim to maintain exclusive right and privilege to my said
Invention.
In witness whereof, I, the said Thomas Parsons, have hereunto set my
hand and seal, this Third day of June, in the year of our Lord One
thousand eight hundred and thinker fam