Improvements in and relating to Door Bell Mechanism for Mechani- cally Ringing Door Bells so as to Imitate Electric Bells, to be Applied in Houses and other Buildings.
Year: 1889

page_text: COMPLETE SPECIFICATION,
Improvements in and relating to Door Bell Mechanism for Mechani-
cally Ringing Door Bells so as to Imitate Electric Bells, to be
Applied in Houses and other Buildings.
1, ALBERT F. ROCKWELL, a citizen of the United States, residing at Bristol, in
the County of Hartford, and State of Connecticut, U.S.A., Mechanic, do hereby
declare the nature of this invention, and in what manner the same is to e
performed, to be particularly described and ascertained in and by the following
statement:
The object of my invention is to make certain improvements in door bell mechanism,
of the class operated by mechanical means, and imitating in sound and appearance
an electrical bell.
In this class of devices a push rod is connected with an ordinary alarm bell
mechanisin in such a way as to require only a slight movement of the push button,
similar to that ordinarily necessary with an electric bell by which to disengage
the alarm mechanism and cause the bell to ring only as long as the push upon the
button is continued. When the push upon the button is discontinued a stop becomes
instantly connected automatically by the retraction of the button with the alarm
mechanism so as to check its action and stop the ringing of the bell.
My invention consists in certain important improvements in this class of door bell
mechanism, which I will first describe in detail by reference to the accompanying
drawings, and then succinctly specify in my appended claims.
In the drawings,
Fig. 1 is a plan view of part of my improvements applied, showing bell wires and
bell cranks, and the hell at a distance from the front door.
Fig. 2 is a section, on the line 2, 2, of Fig. 3.
Fig. 3 is a section on the line 3, 3 of Fig. 2.
Fig. 4 is a diagrammatical viow, showing the use of pulleys and cords instead
of bell wires and hell cranks, illustrating the door bell applied at some distance from
a push button within a house.
Fig. is a section, on line 5, 5, of Fig. 7.
Fig. 6 is a section on line 6, 6, of Fig. 7.
Fig. 7 is a vertical central section of my door bell apparatus.
Fig. 8 is a perspective view of a tappet, striker, and push-rod detached.
Fig. 9 is a vertical section of a part of my apparatus, showing a push-rod and its
relation to a brake-wheel.
Fig. 10 is a similar view, showing a formal modification of the push-rod.
Referring to Figs. 1, 2 and 3 of the drawings, A indicates a section of a door
frame upon which my improvements are applied. B indicates an escutcheon of any
ordinary kind secured to the outside of the frame. Cindicates a frame of clock alarm
mechanism, which may be of any ordinary or suitable kind, not necessary to describe
in detail. D indicates a bell which is secured to an extension D' of the main spring
arhor of the alarm mechanism, so that the main spring may be wound up by turning
the hell. E indicates an internally screw-threaded projection upon the bell, by means
of which it can be screwed to place upon the threaded extension of the main spring
arbor D. Findicates the bell strike, which is of ordinary character, pivoted as
shown to the same pivot to which the tappet G is secured. H indicates the push-
rod, provided with an ordinary button 1, and with a retracting coiled spring K, all
of nsual construction. L indicates a conical stop secured to the inner end of the
push-rod, and adjusted so as normally to bear against one end of the tappet; for the
reason that the coiled spring operates to draw the stop into contact therewith. The
M
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page_text: the tappet but will be turned more or less in use and can be turned specially at
any time, so that wear of the stop will be on all sides of it, and it will therefore
endure in practice much longer than otherwise.
By the use of this device it will be observed that hut slight movement of the button
and push-rod are required to cause the bell to be struck with a clattering stroke, like
-that of an electric bell.
It will also be observed that the stroke will continue as long as the button is
depressed and no longer, as in the case of an electric bell.
It will also be observed that but slight force, merely that necessary to push the
rod against the slight power of the coiled spring is required to cause the bell to
ring, the power directly acting to ring it being the clock work.
To wind up the main spring of the time mechanism, it is only necessary to turn
the bell so that a key is dispensed with.
In Fig. 1, where the bell is shown as applied at a distance from the push-rod,
M indicates a small bell wire, and N the ordinary bell-crank levers.
As the movement to operate my device is but slight, the wire has to be carefully
adjusted, and, in order to provide for variations in tension, due to changes of
temperature, place a small steel wire coiled spring O in the line wire, which will
yield slightly and compensate for any variations of tension in the wire after the original
adjustment of it.
In order to draw the wire towards the bell, when the button is pushed inward so
that it may be so drawn, I provide a small coiled spring P applied to the push-rod,
and of sufficient force to automatically engage and disengage the stop with the tappet
whenever the button is pushed inward or released. This spring P should be smaller
and of less power than the button spring, so that the latter will overcome the force
of the former, and so that the stop will engage with the tappet upon the removal
of pressure upon the button. Thus my device may be made to operate as well at a
distance as when the alarm mechanisin is directly connected with the push-rod to
which the button is applied, and it is a simple economical and complete imitation of
an electrical bell.
By my improvements the ringing of the bell being limited in duration to the push
upon the button, which is generally only instantaneous, it is found in practice that a
single winding of an ordinary main spring, by turning the bell or otherwise, will
conserve force enough to ring the bell, as a rule, for a period of about six months.
Therefore the alarm mechanism need only be wound, at the most, two or three times a
year as a rule.
Referring now to the letters upon Figs. 4 to 10 inclusive of the drawings, A³ indicates
a seotion of a door frame upon which my improvements are applied. B indicates an
escutcheon of an ordinary kind secured to the outside of the frame. C indicates
a common clock alarm mechanism. D2 indicates a bell which is secured to an
extension D³ of the main spring arbor of the alarm mechanism, so that the main
spring may be wound by turning the bell. E indicates an internal screw-threaded
projection upon the bell, by means of which it can be screwed to place upon the
threaded extension of the main spring arbor. F indicates the bell strike, which is of
ordinary character, pivoted as shown to the same pivot F to which the tappet G is
secured. H indicates the push rod provided with an ordinary push button I, and
with a retracting coiled spring K, all of usual construction.
It is necessary that the push-rod be connected either mediately or immediately
with the alarm mechanism in such a manner that a push upon the button sufficient
to overcome the resistance of the spring K and force the push rod inward will result
in releasing the alarm mechanism and setting in operation its train of gears and strike
by the force of the main spring S². It is obvious that the push-rod in some cases,
where the alarm mechanism placeil close to the push button on the inside of a
partition or door way, may be connected directly with some part of the aların
mechanism, for example the tappet, the strike, or one of the gear wheels, so that
normally it will constitute a stop, brake, or checking device to prevent the operation
of the alarm mechanism; and that when pushed inward it will be disconnected and

page_text: will cease the checking or stopping function, so that the alarm mechanism will
operate and the bell will ring as long as the rod thus continues pushed inward and
disconnected from some moving part of the alarm mechanism. But in some cases,
where it is desirable to have the door bell located at some distance from the push
button, as for example in the back end of a hall, it would be better to connect the
push mechanism with the alarm mechanism by means of bell cranks and wires, or by
means of an endless band and pulleys, such as illustrated in the accompanying
drawings.
It is obvious that there are a great variety of mechanical means by the use of levers,
gearing, links, wires, etc. by which the push-rod can be connected, without departing
from the substance of my invention, operatively with the alarm mechanism, in such a
way that when it is pushed inward it will cause the release of the alarm mechanism
and the ringing of the bell for a time coincident with the continuation of the push
upon the button.
By means, however, of a lug or stop L, as shown in Fig. 8, which normally stands
in the way of the action of the bell strike F, but may be pushed inward with the
push rod out of the way of the strike so that the alarm mechanism will operate, all
cases are substantially provided for, in which there needs to be a direct connection
between the push-rod and some moving part of the alarm mechanism. Of course it
is only necessary to release some moving part, not especially the strike, in order to
untasten it and let the alarm mechanism run.
Referring to Figs. 4, 5, and 6, which illustrate one means for applying my
improved door bell mechanism at a distance from a push button and push-rod,
Mdesignates one train of gearing of an alarm mechanism, and N2 another. One of
the main gear wheels O is connected by a ratchet and pawl to the main spring arbor,
to which one end of the main spring is also fixed. The other main gear wheel 0³ is
loose upon the arbor, and is fastened to the opposite, or free end of the main spring.
The result is that the main spring serves to drive both trains of gearing in opposite
directions.
P indicates a pulley secured to one of the shafts P³ of one alarm mechanism.
Qindicates another similar pulley secured to one of the shafts Q3 of the other alarm
mechanism. Passing around each of these pulleys is an endless band R, each band
extending over suitable guide pulleys R³ to another pulley T, which I may call a
brake pulley. This brake pulley is to be located, in practice, in immediate proximity
to the push-rod upon a suitable support or frame Us, and is provided with a brake
spring V (or other braking device), adjusted by means of a screw W to press with
more or less force against the side of the brake pulley to operate as a stop or
brake.
The free end of this brake spring is placed in the path of the push-rod as it is
pressed inward, so that the spring will be pushed out of contact with the brake pulley.
This will release the brake pulley and permit the alarm mechanism to run and the
bell to strike as long as the inward push upon the button and push-rod continue. As
soon as the push is discontinued, the spring V2 will recoil and hear upon the surface
of the brake-pulley and stop the aların mechanism.
Instead of this brake device any other suitable one may be employed, for example
the end of the push-rod might be bent down, as shown in Fig. 10, so as to bear upon
one side of the brake-pulley under tension of the spring K².
I use one of these endless bands, and only one alarm mechanism, whenever it is
desired to ring the bell from only one push-button; but it is sometimes desirable to
provide for ringing a door bell from two points, as for example from a basement
door, and from a front door, and in such a case the double mechanism shown, and the
two endless bands are very convenient.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. In a door bell mechaniam secured within a building the combination of a

page_text: spring push button to be operated from the outside, a bell wire and bell crank
levers connecting the spring push button with the alarm bell mechanism, a push-rod
provided with a retracting spring and connected with the bell wire, a stop upon
the inner end of the push rod for engagement or disengagement with the tappet of
the alarm mechanism, substantially as set forth.
2. In a door bell mechanism secured within a building, the combination of a
spring push button to be operated from the outside, a bell wire and bell crank levers
connecting the spring push button with the alarm bell mechanism, a push rod
provided with a retracting spring and connected with the bell wire, a coil spring P
applied to the push-rod of less power than the button spring, a stop upon the inner
ond of the push rod for engagement or disengagement with the tappet of the alarm
mechanism, substantially as set forth.
3. In a door bell mechanism, the combination of a push button, a push rod to
which the button is attached, a brake connected with the inner end of the push-rod
and adapted to be operated by it, a brake pulley upon which the brake acts, an alarm
mechanism provided with a pulley, and an endless band working on the said pulley
and on the brake pulley, whereby a push upon the push button will cause the ringing
of a bell as long as it is continued, and no longer, substantially as set forth.
4. In a door bell mechanism, the combination of a single bell, two alarm
mechanisms adapted to independently ring the hell, and a main spring having one
end connected to and adapted to operate onc alarm mechanism, and the other end
connected to and adapted to operate the other aların mechanism, whereby the same
bell may be rung by different movements operated by the same power, substantially
as set forth.
Dated this 28th day of August 1889
ALBERT F. ROCKWELL.