Improvements in Type-writers, and in Type to be used therein and for other purposes.
Year: 1896

page_text: Date of Application, 12th Sept., 1896
Complete Specification Left, 9th July, 1897,-Accepted, 14th Aug., 1897.
Improvements in Type-writers, and in Type to be used therein and
for other purposes.
I, WILLIAM LITCHFIELD of 26 Lewisham Park in the County of Kent do hereby
declare the nature of this invention to be as follows:-
In type writers as at present constructed numerous finger keys are required, one
for each character employed, whether it be a capital letter, a small letter, a cipher, a
shorthand sign, a punctuation or the like. Or if one finger key be inade to serve for
two or more separate type the mechanism is complicated thereby.
According to my invention the number of finger keys required in a type writer is
reduced by the employment of type which print different characters when the finger
key is struck with different degrees of force. For this purpose the face of the type is
made duplex, that is to say it has printing surfaces in different planes. Thus, to take
the simplest illustration, the same type may be employed to print a comma and a
semi colon. In this case the comina will stand somewhat higher on the type than
the dot stands; consequently when the key is lightly struck the comma alone prints
but when the key is struck with more force the dot also produces its impression. In
this way, where the alphabets are suitably designed, a great reduction inay be made
in the number of finger keys without in any way complicating the machine.
The type of hand stamp may similarly be made with duplex printing faces.
Dated this 12th day of September 1896.
COMPLETE SPECIFICATON.
Improvements in Type-writers, and in Type to be used therein and
for other purposes..
I, WILLIAM LITCHFIELD, of 26 Lewisham Park, in the County of Kent, 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:-
In type writers as at present constructed numerous finger keys are required, one
for each character employed, whether it be a capital letter, a small letter, a cipher, a
shorthand sign, a punctuation or the like. Or if one finger key be made to serve for
two or more separate type the mechanism is complicated thereby.
According to my invention the number of finger keys required in a type writer is
reduced by the employment of type which print different characters when the finger
key is struck with different degrees of force. For this purpose the face of the type
is made duplex, that is to say it has printing surfaces in different planes. Thus, to

page_text: take the simplest illustration, the same type may be employed to print a comma and
a semi-colon. In this case the comma will stand somewhat higher on the type than
the dot stands; consequently when the key is lightly struck the comma alone prints
but when the key is struck with more force the dot also produces its impression. In
this way, where the alphabets are suitably designed, a great reduction may be made in
the number of finger keys without in any way complicating the machine.
The type of hand stamps may similarly be made with duplex printing faces.
The drawings illustrate the application of the invention to a typewriter producing
a special system of shorthand.
Figure 1 is a table the first column of which shows the symbols produced when
each of the 30 keys is struck lightly and the third column the symbols produced when
the same keys are struck heavily. The second and fourth columns give the letter or
combination corresponding to each symbol.
Figures 2, 4 and 6 are enlarged plan views of the type producing th and thr, t and d,
and tr and dr respectively. Figures 3, 5 and 7 are sections on the lines 3-3, 5-5
and 7-7, of Figures 2, 4 and 6 respectively.
As shown the symbols in column 3 of figure 1 differ from those in column 1 either
by the addition of a line, by the thickening of a line or by both. Figure 2 is an
example of the first and Figures 4 and 6 of the second method. The addition of a
line is produced when the type has surfaces a and b (Figures 2 and 3) at different
levels. The higher surface a is operative whether the key be struck lightly or heavily
whilst the surface b is only operative in the latter case. A thickening of the line is
produced when the projection c on the type, Figures 4 to 7, whose top is the
surface is conical so that the operative part is broader when the key is struck
heavily than when struck lightly.
By similar means three symbols may be produced by the same type but this is
rarely convenient.
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. Type having duplex printing faces namely an upper face which alone prints
when the type is lightly impressed and a lower face which produces an impression
in conjunction with that of the upper face when the type is more heavily
printed.
2. A type writer provided with type substantially as herein described.