AN IMPROVEMENT IN LOCKS, BOLTS, LATCHES, AND OTHER FASTENINGS."
Year: 1862

page_text: LETTERS PATENT to Thomas Pilgrim, of 17, Carlisle Terrace, Fairfield
Road, Bow, London, E., Engineer, for the Invention of "AN IMPROVEMENT
IN LOCKS, BOLTS, LATCHES, AND OTHER FASTENINGS."
PROVISIONAL SPECIFICATION left by the said Thomas Pilgrim at
the Office of the Commissioners of Patents, with his Petition, on the
27th October 1862.
I, THOMAS PILGRIM,. of 17, Carlisle Terrace, Fairfield Road, Bow,
London, E., Engineer, do hereby declare the nature of the said Invention for
"AN IMPROVEMENT IN LOCKS, BOLTS, LATCHES, AND OTHER FASTENINGS," to be as
follows:-
This Invention consists of a supplementary attachment to the inside plate of
the lock, to which is connected the necessary. levers, cranks, and connections
for working the bolts or latches. These arrangements can be applied to any
door, chest, or other locks at present in use, and cannot be opened without a
duplicate key, the latches' and bolts being so contrived as to act simultaneously,
and so to prevent the possibility of their being picked.
The mode of performing the operation of locking or fastening doors fitted
under this Patent is as follows:-When it is desired to use the lock only a
small knob or handle at the back is pushed to the right or left, as the case

page_text: may be, which by a very simple contrivance throws the bolts out of gear, and
when desired to use the bolts in conjunction with the ordinary lock the knob
or handle is to be pushed in the opposite direction. The key for opening this
description of fastening is of the ordinary kind with the addition of a second
set of wards in the direction of its length, and which can be added to any
existing key.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Pilgrim in the Great Seal Patent Office on the
27th April 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
PILGRIM, of 17, Carlisle Terrace, Fairfield Road, Bow, London, E., Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of October, in the year of our
Lord One thousand eight hundred and sixty-two, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Thomas Pilgrim, Her special licence that I, the said-Thomas
Pilgrim, my executors, administrators, and assigns, or such others as I,
the said Thomas Pilgrim, 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 IN LOCKS, BOLTS, LATCHES, AND OTHER FASTENINGS,"
upon the condition (amongst others) that I, the said Thomas Pilgrim,
my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, 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. .
NOW KNOW YE, that I, the said Thomas Pilgrim, do hereby declare
the nature of my 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, that is to say:-
This Invention has for its object an improvement or improvements in locks,

page_text: bolts, latches, and other fastenings, and consists in the addition of a supple-
mentary gravitating or spring lever and bolt fitted to, in, or upon an ordinary
lock so as to be actuated simultaneously with the bolt or latch of such lock
and with the same key, such key being formed with an additional limb for.
actuating the said supplementary bolt or latch. The supplementary bolt or,
latch can be added to locks, latches, and spring bolts as at present fixed to any.
door, chest, or other enclosure. Locks thus constructed, or to which this
improvement is added, cannot be opened without the proper key or a duplicate
thereof. When the addition is made to existing locks the limb for actuating
the supplementary bolt can be added to the ordinary key. The bolt of an ordi-
nary lock fitted with this improvement cannot be actuated without locking or
unlocking the 'supplementary or safety bolt. The lever by which such, safety
bolt is actuated is placed in a separate compartment in the lock and is
inaccessible from the keyhole except by the key with the additional limb
before-mentioned. With the proper key the safety bolt can be actuated
simultaneously with the ordinary bolt.
The mode of locking or fastening a door or other enclosure having a lock
constructed upon this improved principle is as follows, that is to say, when it
is desired to use the ordinary lock bolt alone a small knob or handle at the
back of the lock which acts upon the safety bolt only is pushed to the right or
left, as the case may be, and thus throws this bolt or latch out of gear. In
this case the key, which would otherwise act upon both bolts, now only
operates upon the ordinary bolt of the lock precisely as if the safety bolt were
not added. When it is desired to use both bolts in conjunction the knob or
handle at the back or side is left in its normal position (or pushed back in
the opposite direction to that for throwing the safety bolt out of gear); the
key with the additional limb, if now inserted, will actuate both bolts simul-
taneously. The safety bolt is self-acting by the operation of the gravitating
or spring lever, and in its normal position remains constantly bolted or shot
from the lock and recovers its normal position constantly the instant the
additional limb 'on the key passes a particular point of its revolution. In the
compartment in which the safety bolt is placed I fit a drop locking lever for
locking the safety bolt and ordinary bolt together, so that when both are
locked the latter cannot be moved until this drop lever, which is inaccessible
from the keyhole except by the proper key, is lifted thereby, hence to pick a
common lock of this improved construction becomes an almost, if not absolute
impossibility. A spring may be substituted for the gravitating lever of the
supplen.entary bolt if desired; but I prefer the gravitating principle both for
simplicity and economy of construction and permanent efficiency. This

page_text: improvement is capable of being applied to a number of bolts or latches placed
in different positions upon a door or other enclosing medium, the outlying
bolts being connected with the main lock by suitable links and actuated by
the same key. The form and mode of constructing the improved locks and
applying the said improvements to existing locks are illustrated upon the
accompanying Drawings, to which the following explanation refers.
EXPANATION OF DRAWINGS.
Drawing No. 1.-Fig. 1 is a back view of a lock constructed with the
improvement of my said Invention therein; Fig. 2 is a front or end view of
the same; Figs. 3 and 4, sectional views shewing the interior of the lock;
Fig. 5, the key; Figs. 6, 7, 8, 9, and 10, shews the safety bolt and lever
detached. In these illustrations the same parts of the lock are lettered with
the same letters, so that the following reference applies to the whole.
a is the rim or case of the lock; b, the ordinary bolt moved by the knob c ;
d, the safety bolt; e, the gravitating lever; f, the internal stop or drop lever
for locking the two bolts together; f', the shield or vertical web which carries
the stop; as this lever is moved the stop falls into the notch f* in the safety.
bolt, and as it is hinged to the ordinary bolt and travels with it, and both are
locked, one cannot be moved without the other except when the safety bolt is
thrown out of gear.
Figs. 11, 12, 13, and 14, shew a door latch constructed with my improve-
ments; Figs. 15, 16, 17, & 18, represent an ordinary lock with the safety
bolt added thereto after the same is fixed; Fig. 19 shews the drop locking
lever for locking the bolts together; and Figs. 20 and 21, the mode of fitting
the outlying bolts actuated by the levers y, y.
g, the knob placed under or at the back or side of the lock for throwing the
safety bolt levers and the drop locking stop fout of gear; h, the keyhole
through which the key, Fig 5, is inserted; i, the additional limb of the key
for actuating the safety bolt lever; j, an internal transverse plate enclosing
the keyway of the limbs or wards actuating the ordinary bolt; l, a longi-
tudinal plate separating the safety bolt lever compartment m from the com-
partment; the two webs m' and m², placed as here shewn, effectually protect
the safety lever from being raised except by the key of the peculiar form,
Fig. 5. By inserting the key, Fig. 5, in the keyhole, as shewn, from the side
indicated by the arrow, supposing both bolts locked, the wards n and n' turn
in the compartment marked k and k¹ and operate the bolt b, while the addi-
tional limb i passes into the compartment m and raises the drop lever f out of
the notch, and then raises the lever e, which draws back the safety bolt d, into

page_text: the lock and with it the ordinary bolt; also a second turn of the key to the
position i again now draws, both bolts home and the door, &c., is free. The
safety bolt d, when not required to act, is drawn back and held back by the
lever e of the lever e, which fits into a slot, as shewn at e, Fig. 9. This bolt
is fitted with a friction spring and with a stud e³, by which it is pushed back
by the knob g in the usual way.
Having thus described the nature of my said Invention, and illustrated the
manner in which the same may be carried into effect in practice, I hereby
further declare that I do absolutely restrict myself to the precise detailed
arrangements shewn upon the Drawings, but include as part of my said
Invention all such modification in form and dimensions as are consistent
with the principle of construction thereby illustrated.
In witness whereof, I, the said Thomas Pilgrim, have hereunto set my
hand and seal, this Twenty-seventh day of April, A.D. 1863.
THOS. PILGRIM. (L.S.)