Improved Hammer Mechanism for Typewriting Machines.
Year: 1894

page_text: Cate of Application. 5th Feb., 1894-Accepted, 17th Mar., 1894
COMPLETE SPECIFICATION.
Improved Hammer Mechanism for Typewriting Machines.
A communication from abroad by WILLIAM H. TRAVIS, Manufacturer, of Judson
Place, Philadelphia, Pennsylvania, United States of America.
I, CHARLES AUBREY DAY, Chartered Patent Agent, of 321, High Holborn,
in the County of London, do hereby declare the nature of the said invention, and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention relates to an improved construction of impression hammer adapted
for use upon typewriting machines.
In the accompanying drawings
Fig. 1, is a side elevation of the improved hammer.
Fig. 2, is a longitudinal section showing the hammer in its normal position.
Fig. 3, is a corresponding longitudinal section, showing the hammer thrown out,
as when striking the paper against the type to make an impression, and
Fig. 4, is a transverse section on the line 1-2, Fig. 2.
The saddle or frame A, which carries the hammer, may be of any suitable shape
or construction. In the drawing, its upper part is represented as made in the form
of a horizontal tube a, slotted at the underside, as at a', and practically enclosed
within this tube is the hammer B, and its spiral spring S. The front end of the
tubular portion a is closed by a collar c, which may be made in one with or secured
in the frame A, while near the rear end of the tube is a similar collar c'. I prefer
to make one of these collars removable for convenience of getting at the parts.
The hammer B, is adapted to have a limited horizontal sliding motion within
these guiding collars c, c', and enclosing tube.
The spring S, bears at its forward end upon projections t, carried by the hammer,
and at the rear is acted upon by the legs of the bifurcated upper end of the
operating lever L, which is pivoted to the frame at p, and receives its vibrating
motion from the keys of the type-writing machine through any suitable means.
The projections t, are preferably carried by an adjustable rod T, which passes
through the hammer from the rear end and is there threaded for the reception of
an adjusting nut t¹, by means of which the rod T, may be adjusted longitudinally
to give to the spring any desired tension, that the hammer may give a light or
heavy blow or impact, as the case may require.
Pivoted to lugs e, at the rear of the tubular portion a, of the frame, is a trigger E,
having a catch e', co-operating with a cross-piece b, on a depending lug b', of the
hammer B. When the hammer is drawn back, as shown in Fig. 1, this cross piece
engages with and is held by the catch e', of the trigger E. The lever L, has,
however, an adjustable projection P, in the form of a set-screw to act upon the
forward end of the trigger E, so that when the vibrating operating lever L, is
moved, upon the operation of a key-lever, to throw its upper end forward, as
indicated by the arrow in Fig. 2, it will first compress the spring S, (Fig. 2) and
then the projection P, will strike the underside of the forward end of the trigger E,
raise the latter and release the hammer, which thereupon is thrown forward by
the spring S (Fig. 3.) with an impact force dependent upon the adjustment of
the rod T.
On the return movement of the lever L, a cross-pin p', thereon acts upon the
pendent lug b', of the hammer to return the parts to the positions indicated in
Fig. 1.
It will, therefore, be seen that, under normal conditions, the spring is not com-
pressed, and that the one lever L, performs the several functions of first compressing

page_text: the spring, then acting on the trigger to release the hammer, and finally returning
and resetting the hammer. Furthermore, at the moment the lever has raised the
trigger to release the hammer, the lever is itself also tending to throw the hammer
forward through the medium of the spring.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed I declare that what I
.claim is ;-
1. An impression hammer mechanism for type-writers, comprising a guiding
frame, a movable hammer, a spring to throw the hammer forward, a trigger and a
lever to act upon the spring and also upon the trigger to release the hammer,
substantially as described.
2. An impression hammer mechanism for type-writers, comprising a guiding
frame, a movable hammer, a spring to throw the hammer forward, a trigger and a
lever to act upon the spring and also upon the trigger to release the hammer, the
said lever on its return movement also acting to reset the hammer, substantially as
--described.
3. An impression hammer mechanism for typewriters, comprising a guiding
frame, a sliding hammer, and a spiral spring acting upon the hammer, in com-
bination with an operating lever to act upon the spring and a trigger to hold the
hammer and released by the said lever, substantially as described.
4. An impression hammer mechanism for typewriters comprising a guiding
frame, a sliding hammer, a spiral spring acting at one end upon the hammer, an
operating lever upon which the other end of the spring acts, a trigger to hold the
hammer, and an adjustable projection upon the lever to act upon the trigger,
substantially as described.
5. Au impression hammer mechanism for typewriters, comprising a sliding
hammer and a spiral spring, an operating lever and trigger with a frame having a
tubular portion enclosing the hammer and spring, substantially as described.
6. An impression hammer mechanism for typewriters, comprising a sliding
hammer and spiral spring, with a trigger and operating lever and an adjustable rod
passing through a tubular portion of the hammer and having projections against
which the operating spring acts, substantially as described.
7. An impression bammer mechanism for typewriters, comprising a hammer
having a pendant lug with cross pieces, a spring, a trigger co-operating with said
cross-piece, and an operating lever to act upon the trigger, substantially as
described.
Dated this 5th day of February 1894.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicant.