Compound or Simple Microscope
Year: 1886

page_text: Compound or Simple Microscope.
JAMES SWIFT Optician 81 Tottenham Court Rd London, W. I do hereby declare
the nature of my invention for AN IMPROVEMENT IN SLOW MOTION FOCUSSING
ADJUSTMENT FOR COMPOUND OR SIMPLE MICROSCOPE to be as follows:-
The application of a Lever acting upon one or more flexible steel or other
springy metal pieces connecting the optical tube to the frame of the Microscope:
The said Lever being moved in the usual way by a milled head screw, thus
depressing the flexible springs, & by varying the distance between the end of the
Lever where the depressing screw works to the fulcrum & from the fulcrum to the
lifting point of the Lever, any degree of slowness of action can be obtained by my
improvement. Formerly the aforesaid spring or springs were acted upon directly
with the adjusting screw milled head whereby the degree of motion imparted to
the optical tube was only equal to the pitch or value of screw in giving motion to it
Supposing at thread screw to the inch was used as the motor & one revolution
of this would depress the spring or springs carrying the optical tube to the same
value viz th of an inch, whereas by the introduction of. my Lever the movement
of the optical tube can be reduced to the 10,00ths of an inch or less by, one turn of
the said th thread screw.
What I claim is, the introduction of a Lever between the spring, plates and the
point of the screw giving motion to the same. I also claim that this Lever
governs the travelling rate of the optical tube carrying the objective in & out of
focus;
the speed being influenced by the position of the fulcrum of the Lever to
the lifting point & from the fulcrum to the point where the screw or motion bears.

page_text: An Improvement in Slow Motion Focussing Adjustment for
Compound or Simple Microscope.
JAMES SWIFT Optician, 81, Tottenham Court Road, London W. 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:-
The application of a lever acting upon one or more flexible steel or other
springy metal pieces connecting the optical tube to the frame of the Microscope.
The said lever being moved in the usual way by a milled head screw, thus moving
the flexible springs, and by varying the distance between the end of the lever
where the depressing screw works to the fulcrum & upon the fulcrum to the lifting
point of the lever any degree of slowness of action can be obtained by my
improvement. Formerly the aforesaid spring or springs were acted upon directly
with the adjusting screw milled head, whereby the degree of motion imparted to
the optical tube, was only equal to the pitch or value of screw in giving motion to
it. Supposing at thread screw to the inch was used in the motor & one
revolution of this would depress the spring or springs carrying the optical tube
to the same value viz 11 th of an inch; whereas by the introduction of my lever,"
the movement of the optical tube can be reduced to the 1,000th of an inch or less by
one turn of the said 16 th thread screw.
Description of Diagram A the milled-head screw, the lower extremity of which
acts upon end of lever B..
C. the part carrying optical tube, which is lifted by the fulcrum end of the
lever B.
D. D. are two flexible metal plates, which yield to the action of the lever B
when moved by the screw A. I do not confine myself to the use of two flexible
springs only, as three or more can be employed if found necessary. F is the main
support of the Microscope to which the optical tube E & slow motion adjustment
are fitted.
Having now particularly described and ascertained the nature of my inven-
tion & in what manner the same is to be performed I declare that what
I claim is,
The introduction of a lever between the spring plates & the point of the screw
giving motion to the same. The said lever & screw can also be applied above or
below the aforesaid spring plates.

page_text: I also claim that this lever governs the travelling rate of the optical tube
carrying the objective in & out of focus, the speed being influenced by the position
of the fulcrum of the lever to the lifting point, & upon the fulcrum to the point
where the screw motion bears.
I also claim its application to Lantern projecting" and solar projecting
Microscopes.