A NEW OR IMPROVED ALARUM DETECTOR
Year: 1884

page_text: I WILHELM LÖFFELHARDT of 32 Northampton Square London E.C. Civil
Engineer do hereby declare the nature of my invention for A NEW OR IMPROVED
ALARUM DETECTOR to be as follows:—
My invention relates to improvements in Alarum Detectors and consists of an
apparatus to be connected or attached to those objects which are liable to be lost or
stolen by which means upon the occurrence of such accidents the attention of the
losing party will be attracted or their notice called on audibly and sensibly.
I construct such Alarum Detectors in the following manner.
Within a suitable casing of any desired form provided with a number of sound
holes I provide a bell or other suitable sound giving device adapted to be sounded
by a blow or stroke this bell or annunciator is surrounded by a cylinder connected
with a spring-box or barrel. At one end this cylinder is formed or provided with a
number of holes uniformly arranged on its circumference, whilst around the other
part a cord band or other suitable connecting means is wound adapted to be
attached to the objects to be protected. The cylinder with the spring-box or barrel
revolves on a pivot or centre affixed to the said casing and that end of the spiral
spring which is not attached to the barrel is connected with this pivot or centre.
The perforations of the cylinder allow a spring-hammer or sonnorator which is also
fastened outside of the cylinder to said casing to strike the bell or cause the sound
giving means to be operated at intervals governed by the distances apart of the
said perforations when the cylinder is caused to rotate. This operation will happen
as soon as the object attached to the said cord band strap or other connecting
means is drawn upon so that it commences winding off from the cylinder in con-
sequence of a pull upon that connection which will thereby cause the drum or
cylinder to be rotated and the sounds emitted will serve to warn or alarm the
wearer and notify to him the fact of his loss or that a theft is being attempted.
In case the strap cord or connection should be cut asunder by a thief never-
theless the drum will rotate but its direction of revolution will be in a reverse
direction by reason of the tension of the spiral spring in the barrel, and in its
revolution the strokes of the hammer will not only cause the sounding of the bell,
IPrice 1

page_text: but they will also effect sensible vibrations or tremors somewhat like those from an
electrical machine supposing the Alarum Detector to be kept close to the body of
the wearer.
Instead of a bell or like annunciator being employed a pair of friction-rings may
be used one of which to be fastened to the casing the other to the rotating drum or
cylinder causing a shrill or other attention attracting sound in consequence of the
friction of the rings one upon another.
In employing such frictional rings or sonnorators the opening in the drum and
the spring-hammer may be dispensed with.
the purpose
The arrangement form and size of the apparatus will depend upon
for which the employment of the same is intended and whether it is to be used to
protect portable or stationary objects and on other circumstances.

page_text: COMPLETE SPECIFICATION.
I WILHELM LÖFFELHARDT of 32 Northampton Square London E.C Civil
Engineer do hereby declare the nature of my invention for A NEW OR IMPROVED
ALARUM DETECTOR and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
My invention relates to improvements in Alarum Detectors and consists of an
apparatus to be connected or attached to those objects which are liable to be lost or
stolen, by which means upon the occurrence of such accidents or events the
attention of the losing party will be attracted or their notice called on audibly and
sensibly.
I construct such Alarum Detectors in the following manner.
Within a suitable casing of any desired form provided with a number of sound
holes I provide a bell or other suitable sound giving device adapted to be sounded
by a blow or stroke, this bell or annunciator is surrounded by a cylinder connected
with a spring-box or barrel.
At one end this cylinder is formed or provided with a number of holes uniformly
arranged on its circumference, whilst around the other part a cord, band or other
suitable connecting means is wound adapted to be attached to the objects to be
protected, the cylinder with the spring-box or barrel revolves on a pivot or centre
affixed to the said casing and that end of the spiral spring which is not attached to
the barrel is connected with this pivot or centre.
The perforations of the cylinder allow a spring hammer or sonnorator which is
also fastened outside of the cylinder to said casing to strike the bell or cause the
sound giving means to be operated at intervals governed by the distances apart of
the said perforations when the cylinder is caused to rotate. This operation will
happen as soon as the object attached to the said cord, band, strap or other con-
necting means is drawn upon so that it commences winding off from the cylinder
in consequence of a pull upon that connection, which will thereby cause the drum
or cylinder to be rotated and the sounds emitted will serve to warn or alarm the
wearer and notify to him the fact of his loss or that a theft is being attempted.
Even if the strap, cord or connection be cut asunder by a thief, the drum will
rotate but its direction of revolution will be in a reverse direction by reason of
the tension of the spiral spring in the barrel; and in its revolution the strokes of
the hammer will not only cause the sounding of the bell, but they will also effect
sensible vibrations or tremors somewhat like those from an electrical machine
supposing the Alarum Detector to be kept close to the body of the wearer.
Instead of a bell there may be employed a pair of friction-rings, one being
fastened to the casing; the other to the rotating drum or cylinder causing a shrill
or other attention attracting sound caused by the friction of the rings one upon
another.
In employing such frictional rings or sonnorators the opening in the drum and
the spring-hammer may be dispensed with.
The arrangement, form and size of the apparatus will depend upon the purpose
for which the same is intended and whether it is to be used to protect portable or
stationary objects and on other circumstances.

page_text: In order to make my invention more clearly understood I will describe it with
reference to the accompanying drawing, in which figs 1 to 4 illustrate an alarum
detector provided with a bell. Fig. 1 is a front view of the alarum detector, from
which the front cover is removed, fig. 2 is a sectional side elevation, fig. 3 is a side
elevation after cutting away a part of the shell or casing, fig. 4 is a side elevation.
b is the casing of the apparatus provided with a number of sound holes a. c is the
central axis of the cylinder d; e is the perforated part of such cylinder through
the holes of which passes the head of the hammer or sonnorator i. f is the string
or ribbon of steel, cloth or other suitable material for connecting the object to be
secured with the alarum detector; such string or ribbon is wound ordinarily
around the cylinder d by means of spring h within the spring-box or barrel g
fastened concentrically to the cylinder d.. kis the bell; Z the hook or ring for
attaching the object to be secured and m the pendant for fastening the alarum
detector at its proper place.
A modification of the above construction is shown in figs 5 and 6, fig. 5 being a
front view of the detector from which the front cover is supposed to be taken away;
fig. 6 is a sectional side elevation thereof. The hammer or sonnorator i is fastened
inside the cylinder or drum d and moved by means of a finger pivoted at i³,
which oscillates, when the cylinder d rotates, by means of the star wheel e² fixed to
the central axis c.
Figs 7 and 8 illustrate an alarum detector provided with friction rings x y
instead of the bell. The ring x is fastened to the casing or shell b, the ring y to
the rotating drum or cylinder d of my apparatus, causing a shrill sound in con-
sequence of the friction of the rings one upon another as soon as the strap fis
winding off from the cylinder as above mentioned with reference to the analogous
apparatus described.
In order to obtain a close but nevertheless elastical sliding of the rings against
each other, the cylinder d, whereon the ring y is fastened, is pressed towards the
ring by means of the spring z.
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
1. In alarum detectors the combination of the string or ribbon f with the
moveable cylinder d, its perforated part e, the hammer or sonnorator i, the bell k,
the spring-box g and the spring h, substantially as described and illustrated by
figs 1 to 4.
2. In alarum detectors the combination of the string or ribbon the movable
cylinder d, the hammer or sonnorator i and the finger it with the star wheel c',
substantially as described and illustrated by figs 5 and 6.
3. In alarum detectors the combination of the string or ribbon fand the movable
cylinder d with the friction rings y and x and the spring z substantially as described
and illustrated by figs 7 and 8.