AN IMPROVED OBJECT STAGE FOR MICROSCOPES
Year: 1877

page_text: LETTERS PATENT to Francis Herbert Wenham, of No. 8, Oxford Road, Ealing,
in the County of Middlesex, Engineer, for the Invention of "AN IMPROVED
OBJECT STAGE FOR MICROSCOPES.”
Sealed the 14th August 1877, in pursuance of an Order of the Lord Chancellor, and
dated the 6th February 1877
PROVISIONAL SPECIFICATION left by the said Francis Herbert Wenham at
the Office of the Commissioners of Patents on the 6th February 1877.
FRANCIS HERBERT WENHAM, of No. 8, Oxford Road, Ealing, in the County of
Middlesex, Engineer. "AN IMPROVED OBJECT STAGE FOR MICROSCOPES."
By this Invention an extremely thin object stage which admits rays of light of
great obliquity to illuminate objects under examination may be made having only
one traversing plate to which rectangular movements are given as follows:-In the
fixed or base plate of the stage is cut a transverse, dovetailed, or undercut groove,
near to one side, into which slides a strip of metal, the plane of which is level with
the top of the base plate. This sliding piece carries two blocks, between which a
tail piece forming part of the top or movable plate slides in a direction at right
angles to the transverse slide. In the top of these two blocks are bearings for
carrying a pinion which moves the top plate to and fro by means of a rack fixed to
the tail piece. The pinion is turned by a milled head attached to the base plate by
a suitable bearing. The axis of this milled head is made hollow to receive a squared
prolongation of the pinion which slides therein during the movement of the trans-
verse slide. The transverse movement is obtained by a second milled head attached
to the outer face of the first one, but free to rotate thereon. The axis of this outer .
milled head is tapped to receive a screw upon the squared end of the pinion. When
the two milled heads are rotated together motion is given to the top plate in a
direction to or from the axis of the pinion, but when the outer milled head only is
moved the transverse slide alone comes into action, and the plate moves parallel
with the pinion or at right angles to the other motion.
The object stage herein described is applicable to the usual form of microscopes,
but on account of its thinness is specially adapted to the microscope patented.on
Die

page_text: 1st day of August, 1876, & Numbered 3078, by John Stuart, a communication
from abroad by Joseph Zentmayer, of Philadelphia, United States of America.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Francis Herbert Wenham in the Great Seal Patent Office on the
14th August 1877.
FRANCIS HERBERT WENHAM, of No. 8, Oxford Road, Ealing, in the County of
Middlesex, Engineer. "AN IMPROVED OBJECT STAGE FOR MICROSCOPES."
This Invention has for its object improvements in object stages of microscopes,
having the usual rectangular movements, by means of which said improvements an
extremely thin object stage which admits rays of light of great obliquity to illu-
minate objects under microscopic examination may be made, such object stage
having only one traversing plate to which rectangular movements are given.
Having thus described the nature of my said Invention, I will now by the aid of
the accompanying Drawings describe more particularly the manner in which tho
same may be performed or carried into effect; in each of the Figures in the said
Drawings the same letters of reference indicate the same or corresponding parts.
Figure 1 represents a plan view of the stage, a portion of the working parts being
in section; and Figure 2 is a section through the dotted line Y, Z, on Figure 1.
In the fixed or base plate of the stage A, A, is cut a transverse, dovetailed, or
undercut groove B, B, near to one side, into which slidos a strip of metal C, the
plane of which is level with the top of the base plate A, A. This sliding piece C
Carries two blocks D, D, between which a tail picce E, E, forming part of the top
or moveable plate F, F, slides in a direction at right angles to the transverse groove
B, B. In the top of these two blocks D, D, are bearings for carrying a pinion G
which moves the top plate F, F, to and fro by means of a rack or racks H, H, fixed
to the tail piece E, E. The pinion G is turned by a milled head I attached to the
base plate A, A, by a bearing M. The axis of the milled head I is made hollow to
receive a square prolongation J of the pinion G which slides therein during the move-
ment of the transverse slide C. The transverse movement is obtained by a second
milled head K attached to the outer face of the first one I, but free to rotate thereon.
The axis of this outer milled head K is tapped to receive a screw L upon the squared
end of the pinion G. When the two milled heads I and K are rotated together
motion is given to the top plate F, F, in a direction to and from the axis of the
pinion G; but when the outer milled head K only is moved the transverse slide C
only comes into action, and the plate F, F, moves parallel with the pinion G, and at
right angles to the other motion.
The object stage herein described is applicable to the usual forms of microscopes,
but on account of its thinness is specially adapted to the microscope patented on
the First day of August, 1876 [No. 3078], by John Stuart, a communication from
abroad by Joseph Zentmayer, of Philadelphia, in the United States of America,
Optician.
Having thus particularly described and ascertained the nature of the said Inven-
tion, and the manner in which the saine may be performed or carried into effect, I
would remark that I am aware that microscope stages have long been made in
which the rectangular movements of the stage have been obtained by means of two
independent milled heads turning in the same axial line, and therefore I make no
claim to the use of such two milled heads in the same axial line; but what I claim
as novel is the prolonged end of the pinion sliding within the axis of the milled
head I, as described and shewn in the Drawings.

page_text: I also claim the general arrangement of the parts of the object stage, as described
and shewn in the Drawings.
In witness whereof, I, the said Francis Herbert Wenham, have hereunto set
my hand and seal, this Thirteenth day of August, in the year of our Lord.
One thousand eight hundred and seventy-seven.
FRANCIS HERBERT WENHAM. (L.S.)