IMPROVEMENTS IN ALARM- LATCHES
Year: 1884

page_text: I ARTHUR CHARLES HENDERSON of 47 Museum Street Oxford Street in the
Parish of Bloomsbury and county of Middlesex, Civil Engineer and Patent Agent
do hereby declare the nature of the said Invention for " IMPROVEMENTS IN ALARM-
LATCHES A communication to me from abroad by Onésime Blanchot, Japanner of
the city of Paris in the Republic of France to be as follows:-
33
This invention is intended either to give notice of the entry of persons into
shops, apartments, offices and so forth, or as a burglar alarm in private dwellings,
or establishments of various descriptions.
The alarm can be rendered inoperative for any length of time when so required.
The shaft of the handle which starts the alarm on turning it, fits into a square
socket which turns freely in a circular box or case at the lower extremity of the
apparatus, as well as in the bed plate of the latch.
Cast with the socket is an arm which actuates the alarm mechanism when the
handle of the latch is manœuvred.
Round the socket is a kind of muffle at the base of which are two notches fitting
on projections in the circular case or box alluded to, and surrounding this latter are
coiled two springs, two of whose ends are fixed to the muffle, whilst one of their
free ends presses against the shoulder of the latch or bolt, keeping it constantly out,
whilst the free end of the other spring acts on a pin on the arm of the muffle.
The latch acts in the usual manner, that is to say on turning the handle it is
drawn into the box, and on releasing the handle one of the springs which was
compressed expands and fastens the door by shooting out the bolt or latch.
The arm of the muffle pivots with the socket and simultaneously by its end,
operates on the end of a lever, which in turning transforms by its other end, the
oscillatory movement into one of drawing on a hooked piece which catches on the
hammer and causes it to strike the bell.
A spring brings back the hooked piece into its normal position after it has acted
on the hammer for striking the bell.
The bell which is an ordinary alarm one, is mounted on a shaft, and is adjusted
by a rimmed screw, and is enclosed in a case with ornamental openings for the
escape of sound.
When not required the bell can be removed.
·

page_text: I ARTHUR CHARLES HENDERSON of 47 Museum Street, Oxford Street in the
Parish of Bloomsbury and county of Middlesex Civil Engineer and Patent Agent
do hereby declare the nature of the said invention for "IMPROVEMENTS IN ALARM
LATCHES, a communication to me from abroad by François Onesime Blanchot,
metal polisher of the city of Paris in the Republic of France, and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement to be as follows:-
The improved alarm bolt or latch herein referred to, is intended either to give
notice of the entry of persons into shops, apartments or offices, or as a burglar
alarm in private dwellings, or in public establishments of various descriptions, it
being impossible to turn the handle of the door without ringing the bell sufficiently
loud to be heard in any part of the building; the ring may as required be either
simple or repeated.
Alarms of the ordinary description are usually separate from the latch, but
in this case it is in combination, and forms part of the appliance, without in
any way increasing the dimensions, or sensibly augmenting the price, of such
articles.
The mechanism for effecting the desired result is both simple and economical it
being readily attached to the door by any one, it being merely fixed by two
screws. At the same time the bell is arranged that it can at any time be rendered
inoperative when so desired.
Figs 1 and 2 of the accompanying drawings represent an alarm latch of the
description embodying my invention, shown in front and side elevation.
Fig 3 represents the same, the case and bell being removed to show the works,
the position of the bell is shown in dotted lines.
Fig 4 is a vertical section showing the bell and the socket hereafter mentioned.
Figs 5 to 8 are some of the principal parts of the mechanism shown in detail.
The case a which is in general aspect somewhat similar to articles of this nature,
is or may be of cast metal, brass, copper and so forth, b is the socket for the
reception of the handle shaft. The bell being situated at c where the case is
pierced in front and at the sides, so that the sound may escape freely.
The socket b, is cut square for the reception of the shaft of the handle x, and is
cast with an arin b' which actuates the bolt or latch p, and bell.
It turns in an opening in the case or box containing the whole mechanism
which is closed by the plate d, by which the apparatus is fixed to the upright
of the door.
A muffle with collar f¹ (Figs 3. 4 and 8) is mounted on the socket, this collar
is pierced with two mortises f¹ƒ³ to receive two projections on the case or box,
and which form stops or checks to the muffle f.
Two spiral springs r. surrounds the muffle f, one of their ends being fixed to it
by hooking to a lateral projection ƒ of the collar f1.
The spring r, acts at its free end on the bolt or latch p; in like manner the free
end of the spring r¹, rests against a pin 62 fixed on the arm b¹ of the socket. This
spring assists in opening the door and latch in turning the handle, and the
spring r, acts on the latch when the handle ceases to be turned.

page_text: The arm 6¹, whilst actuating the bolt or latch p (by aid of a hollow b³ Fig 7) at
the same time acts on the tail end g, of a lever which pivots at g¹, and whose other
end g, is articulated to a piece h, intended to transform the drawing motion it
receives, into an oscillatory one on the support k, of the hammer m, of the bell t,'
vide Figs 5 and 6 which are details of the pieces g, and h.
For this purpose the piece hooks to the support k under the influence of
a spring, but leaves it, when the lever g, draws it sufficiently in the direction of
the arrow (Fig 3).
The bell support k pivoting at 1 under the influence of the spring n. which
brings it sharply to its normal position of repose when it is released from the
piece h, by this rapid movement causes the hammer to strike the bell t.
This latter is screwed to the end of a shaft q rivited on the plate d.
The part t¹, of the bell forming a nut or knob on the shaft g. which passes outside
the case or admits of heightening or lowering the bell or in removing it to prevent
or arrest its action.
It is fixed in either of these positions by turning the rimmed nuts which has its
fulcrum on the case a.
The action of the apparatus is as follows:-The latch acts in the same manner as
is customary with such appliances, by turning the handle x, the socket b, and arm 6¹,
communicate motion to the latch or bolt p, causing it to enter the box a, at the
same time the lever g. g¹ g² is acted on which draws the piece h, causing the
hammer support to pivot and releases it quickly to produce the automatic shock of
the hammer on the bell and then return it to its normal position.
All action on the handle ceasing, one of the springs r shoots the bolt out, and the
other effects its return to the normal position.
v, is an ordinary bolt which when desired is shot into the notch p¹ of the
bolt p, for checking its movement. y. y are screws by which the apparatus is
fixed on the door.
Figs 9 and 10 show the method employed for prolonging the ring of the bell,
which is effected by gear work.
Fig 9 shows the internal mechanism, the bell being shown only in dotted lines.
Fig 10 is a vertical section of the same.
The socket 6 receives the square shaft of the handle, the arm b¹ which commu-
nicates motion to the bolt p, and to the bell has its upper part at 6 hollowed for
the reception of the end c of a toothed sector c¹ articulated to an axis c¹¹, riveted
to the plate d. concentrically with this axis; this sector gears with a pinion f fixed
to a toothed wheel e, which communicates the rotary motion it receives to a
pinion g, as shown by Fig 10, this pinion g is mounted loosely on the shaft q
which latter is riveted to the plate d, and supports the belt t.
The pinion g is mounted on the arın g¹ to which is articulated the hammer m, at
the end g of this same arm. In order to allow of the passage of the body of the
pinion, the sector c is open at x, being provided at this point with an aperture
concentric with its point of rotation.
The sector c, is likewise furnished with a projection x¹, which forms an abutment
when it makes the return movement.
As in the preceding case the socket b is surrounded by a muffle f¹ with collar f",
a spiral spring r, surrounds this muffle, and with its extremity, acts upon the
pin 62 for leading the socket to the closed position.
In lieu of the spring for actuating the bolt or latch as.herein described one or
other of the following arrangements may be used, vide Figs 9 and 10.
The bolt is set in a rectangular mortise p¹, being furnished with a spiral spring
at p2, which operates on the bolt.
A projection o cast with the case a, forms a stop, and regulates the displacement
of the bolt.
The action of the latch is similar to that already described, that is to say by
rotation of the handle, the socket b, transmits this movement to the bolt p, by its

page_text: arm b, which at the same time causes the sector c to turn and consequently the
pinion, which is solid with the wheel e, and causes it to revolve.
This wheel e, gears with the pinion g, which bears the hammer, it will
consequently be understood that the latter will continue to strike the bell during
the whole time the sector turns; that is to say from the time of its departure to
its return to the normal position. The advantage of this system therefore is that
the ringing of the bell is sustained, and may be prolonged as desired.
The bell may be made to ring as the hammer makes its forward and return
movement, or simply in starting or in returning. Or in lieu of this kind of alarm
an ordinary clock alarm may be employed.
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
1st The usuel method of adapting an alarm to bolts and latches which also serve
as locks, the external form and dimensions of which are similar to the simple and
ordinary bolts, without increasing their proportions.
2nd The method of surrounding the socket b, with a muffle f, with collar f1,
encircled with two spiral springs r., one of which acts on the bolt, and the other
on the lever b¹ vide Figs 1 to 8. The said socket being mounted in a particular
manner in the case a, and covering plate d, in the manner and for the purposes
precisely as herein setforth.
3rd The method of, and means employed for connecting the bolt movement with
that of the bell alarm, by means of the arm or lever b¹ of the socket b, which
simultaneously actuates the bolt p, and lever g. g¹ g² of the ringing mechanism.
Figs 1 to 8.
4th The mode of mounting the bell on the shaft q, so that it can be brought into
position so that the hammer may strike it, or so that it can be withdrawn from its
reach, by adjusting it as required by means of the rimmed knob s. which admits of
the use of the bolt either with or without the alarm, also allowing of turning the
bell is case of wear.
5th The method of grouping the several parts of the ringing mechanism on the
plate d, of the case a, as already described, and as shown Fig 3.
6th The employment of gear work for effecting either a sustained and continuous
alarm or a simple ring produced by aid of the arm or lever b₁ of the socket b,
operating on the hammer m, which latter continues striking the bell during the
whole time occupied in either opening or closing the door (as represented by Figs 9
and 10).
7th The method of, and the means employed for substituting for the spring r
Figs 1 to 8, a recess cut on the bolt in which a spiral spring p² is situated and
actuates it, closing or shooting it when it is abandoned by the socket vide Figs 9
and 10.
8th The adaptation of the invention to existing bolts and latches or locks with
or without keys, together with the right of varying the form and dimensions of the
several parts of the mechanism, which can readily be effected without departing
from the principle of action, and in manufacturing the apparatus in any suitable
metal, and by the means which proves the most economical