Improvements in Type-writing Machines.
Year: 1890

page_text: Date of Application, 8th July, 1890-Accepted, 16th Aug., 18:0
COMPLETE
SPECIFICATION.
[Communicated from abroad by THE FITCH TYPE WRITER COMPANY, a corporation
incorporated under the laws of the State of Florida, domiciled at Des Moines,
Iowa, Manufacturers of Type Writers.]
Improvements in Type-writing Machines.
I, WILLIAM BOTTOMLEY, of 154 St. Vincent Street, Glasgow, in the County of
Lanark, North Britain, Patent Agent, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
Type-writing machines in common use have a paper carriage propelled by spring
under or over the point of impact of the type upon the platen. A step-by-step
escapement releases the carriage and then holds it, for each depression of a key-lever.
The escapement consists ordinarily of a long single or double track and a single or
double pawl or stop. Customarily where single pawls are used, it has had a single
tooth to engage a double rack, while when a double pawl or stop is used, one part
hinged to the other, each part has had but one tooth.
This invention has the following features :-
I use a single rack, and make the teeth of both rack and stop of saw-tooth form
with the working faces at right angles to the line of movement of the paper carriage.
The stops consist of two short racks, one sliding on the other and guided in a
straight path parallel to the long rack by straight guides of any character. The teeth
of any rack are in a straight line so that all the faces in contact will bear throughout
their whole extent, and wear will be distributed over the whole working face of each
tooth. Such teeth, with the ordinary wear occuring on a type-writer, will last
almost indefinitely and far outlive an escapement in which each tooth bears but one
point of its working face.
The accompanying drawing shows the invention applied to a machine in which
the long rack moves with the carriage, and the stops are mounted directly on the
stationary frame, but it will be apparent that the Invention is equally applicable to
the reverse case wherein the long rack is mounted on the stationary frame and the
stops are carried by the paper carriage.
In said drawings:-
Figure 1. is a sectional elevation of portions of a type-writing machinė embodying
my Invention all parts being removed which are not necessary to the understanding
of my improvement.
Figure 2. is a plain view of the same.
Figure 3. is a plain view on a large scale of the three racks forming the step-by-
step escapement.
Figure 4. is an edge view of the sliding short rack.
Figure 5. is a side view or projection of the stirrup hereinafter referred to.
1. is a long rack, and 2, 3 are two short racks having their teeth arranged to
mesh with those of rack 1. The rack 1. has a pivot 4 at each end to hang it from
the paper, and suitable means (not shown) are provided for vibrating or tilting the
rack from one to the other of racks 2, 3. The teeth of each rack being in a straight
line, and their bearing or working faces being at right angles to their length, their
bearing and consequently their wear is distributed over the entire working surface of
every tooth in mesh.
The rack 2 is fixed to any suitable part 5 of the frame, and the rack 3 slides
thereon, being guided parallel to rack 1 by screws or studs 6, 7 and open slots 8, 9.
A spiral, or other suitable spring 10 is attached at suitable points to the two
racks 2, 3, as for example, to screw 6 and pin 11, and tends to impart to rack 3 a
movement the reverse of that had longitudinally by rack 1 and the paper carriage.

page_text: Thus when the rack 1 is vibrated or tilted downward from rack 3 (in engagement
with which it nominally rests) to rack 2, the rack 3 will be released and will be
pulled or thrown by springs 10 past any desired number of teeth of rack 1 in the
direction indicated by the arrow a until arrested by a stop pin 12. When therefore
the rack 1 is allowed to raise so that it is released by fixed rack 2, it is drawn by
customary springs (not shown) in the direction of arrow b, carrying with it rack 3,
with which it meshes immediately on leaving rack 2. This motion of rack 3 is
arrested by the impingement of the inner end of slot 8 on stud or screw 7 and
movement of rack 1 and paper carriage held until the rack 1 is again vibrated. It
will be seen that every tooth of one or other of racks 2, 3 has its entire working face
(which I have designated by the letter c) in contact with the corresponding faces of
the teeth of rack 1.
•
To adjust the throw of rack 3 so that it will travel over a greater or less number of
teeth of rack 1, it has two or more seats 13 for the stop-pin 12, and the said pin is
carried by a rock-shaft 14 mounted in brackets 15 of the stationary frame. An
arm 16 on said rock-shaft supports a stirrup or stop 17, with which a lever 18
engages. The said lever may have a suitable key, and is so pivoted that its depression
or elevation will throw the pin 12 opposite one or other of seats 13 on rack 3, and so
'adjust the throw of said rack. Such an adjustment is especially desirable in adapting
the length of feed to the width of the character printed, as, to small or capital
letters.
It is obviously immaterial whether the racks be arranged vertical or as shown, in
'a horizontal plane.
$:
1
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
claim is
-
1. The arrangement of 3 straight racks, substantially in the manner shown and
described, whereby the friction and wear is distributed over a number of teeth..
2. The making of the bearing or engaging faces of such teeth parallel and
equidistant in furtherance of the same end.
3. The adjustable stop for such racks, substantially as shown and described.
Dated this 7th day of July 1890.
July 1890.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.