Im- PROVEMENTS IN APPARATUS FOR CONVERTING CIRCULAR OR ROTARY MOTION INTO ALTERNATE RECTILINEAR MOTION
Year: 1861

page_text: DIADCCA UT
of Middlesex. Patent Agents and Engineers. for the Invention of "Im-
PROVEMENTS IN APPARATUS FOR CONVERTING CIRCULAR OR ROTARY MOTION
INTO ALTERNATE RECTILINEAR MOTION."--A communication from abroad
by M. Francois Normand, Engineer, of Paris. in the Empire of
France.
Sealed the 12th November 1861. and dated the 27th May 1861.
PROVISIONAL SPECIFICATION left by the said George Henry Birkbeck
at the Office of the Commissioners of Patents, with his Petition. on the
27th May 1861.
I. GEORGE HENRY BIRKBECK, of the Firm of Tongue & Birkbeck. of 34. .
Southampton Buildings. Chancery Lane, in the County of Middlesex, Patent
Agents and Engineers, do hereby declare, the nature of the invention for "Iм-
PROVEMENTS IN APPARATUS FOR CONVERTING CIRCULAR OR ROTARY MOTION INTO
ALTERNATE RECTILINEAR MOTION," to be as follows:-
This invention relates to an improved arrangement of apparatus for
converting circular or rotary motion into alternating rectilinear motion, and is
particularly applicable to printing presses. and to other machines where an
universal joint is employed for transmitting the circular motion of an axis to
produce an alternate to-and-fro movement in other parts of such machines..
and the object of these improvements is to obtain a more equable motion 10
mechanism of this kind than heretofore.. For this purpose the arms connected
to the fork of the universal joint are of considerable length, and are otherwise

page_text: suitably arranged, by which the angle at which the axis of the toothed pinion
which takes into the toothed rack may be greatly increased, and the irregularity
in the working is avoided by forming the toothed pinion slightly oval or
elliptical, in place of circular, with a suitable arrangement of the teeth, which
teeth work into the teeth of the rack, which are similarly arranged to those of
the ninion
fictters Latent, meu
by the said George Henry Birkbeck in the Great Seal Patent Office on
the 27th November 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
HENRY BIRKBECK, of the Firm of Tongue & Birkbeck, of 34, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Patent Agents and
Engineers, send greeting..
--WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent. hearing date the Twenty-seventh day of May, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and surcessors, give and grant unto me,
the said George Henry Birkbeck, Her special licence that I, the said George
Henry Birkbeck, my executors, administrators, and assigns, or such others as
I, the said George Henry Birkbeck, my executors, administrators, and assigns,
should at any time agree with, and no others. from time to tinic and at all
times thereafter during the term therein expressed. should and lawfully might
make, use, exercise. and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN APPARATUS FOR CONVERTING CIRCULAR OR ROTARY MOTION INTO ALTERNATE
RECTILINEAR MOTION," a communication to me from abroad by M. Francois
Normand, Engineer, of Paris, in the Empire of France, upon the condition
(amongst others) that I. the said George Henry Birkbeck, my executors or
administrators, by an instrument in writing under my, or their. or one of their
hands and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and cause
the same to be filed in the great Seal Pata
within six calendar
month next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Henry Birkbeck, do hereby
declare the nature of the said Invention, and in what manner the sime
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say:

page_text: This Invention relates to an improved arrangement of apparatus for
converting circular or rotary motion into alternating rectilinear motion, and is
particularly applicable to printing presses, and to other machines where an
universal joint is employed for transmitting the circular motion of an axis to
produce an alternate to-and-fro movement in other parts of such machines.
and the object of these improvements is to obtain a more equable motion to
mechanism of this kind than heretofore. For this purpose the arms connected
to the fork of the universal joint are of considerable length, and are otherwise
suitably arranged, by which the angle at which the axis of the toothed pinion
which takes into the toothed rack may be greatly increased. and the irregularity
in the working is avoided by forming the toothed pinion slightly oval or
elliptical, in place of circular, with a suitable arrangement of the teeth, which
teeth work into the teeth of the rack, which are similarly arranged to those of
the pinion.
Having thus stated the nature of the Invention. I will proceed to describe
more fully the manner in which the same is carried into practice. together
with the Drawing hereunto annexed, and as these improvements are more
particularly applicable to printing presses, and other machines in which a
"cardan" or universal joint is used. it may be desirable in notice the defects
and inconveniences occasioned by the use of the present joint. which this
Invention is intended to obviate.
From the origin of printing presses to the present time all those which have
been constructed with the "cardan" joint (to avoid the complications of the
parallelogram) admit of considerable improvement in relation to the precision
and evenness of their working. These presses cannot be employed without
having some play in the teeth so as to cause the rollers to hold on the blocks
of the imposing stone, to avoid the "slurring." This defect is increased in
proportion as the size of the paper is enlarged. If it is desired to accelerate
the speed for the purpose of obtaining a better "touch." the diameter of the
pinion of the rack must naturally be increased, the inclination of the moveable
axis then becomes an obstacle. for when it exceeds 12 or 14 degrees unsatis-
factory results are obtained. In presses for printing newspapers. going at
great speed, called reacting presses, the above number of degrees cannot be
increased without causing a "slurring" effect. since in this description of press
it is the imposing stone which controls the rollers, producing numerous little
folds or creases objectionable to readers, although not of sufficient consequence
to cause the sheets to be rejected. This defect also occurs owing to the excess
of the inclination before stated. as the sheet on its return in passing over the
wooden cylinder (which is regulated by the first or fixed part of the motion

page_text: shaft, turning constantly in one direction) is pushed and pulled alternately by
the pressure rollers, which are governed irregularly by the inclined moveable
spindle or shaft forming the second part of the motion shaft. The regularity
.or adjustments are re-established every quarter of a turn when the forks of the
joint are horizontal or vertical to the opening of the guide of the moving shaft,
but during this passage only, in such a manner that the irregularity is constant
and reaches with an inclination of 22 degrees in the shaft, a difference
of 0003 on a circumference of 0.069, sometimes in advance, and sometimes in
arrear, as may be seen on examining Figure 3 of the Drawing at the point J,
between the two lines dotted red and black. In the presses now in use the
inclination does not reach even 19 degrees, and in those which give the best
results it is under 10 degrees, but for long movements of the table it is
necessary to diminish the speed, for with the small inclinations which require
small pinions (there are some which make eight revolutions in travelling to and
fro) the dead point operates (four times) more rapidly than the wheel or
handle. The chances of rupture are thus increased if the inclination of the
shaft is diminished, and if increased to pass more easily in the turnings, the
irregularity of the speed increases, and produces the numerous bad results of
such imperfect construction. To avoid these defects the arrangements of
apparatus shown in the Drawing attached are employed for this purpose.
DESCRIPTION OF THE DRAWING.
Figure 1 shows a longitudinal elevation of the moving shaft, together with
the improved arrangement and modification of the universal joint; Figure 2
the improved arrangement and modification of the universal joint; Figure 2
shows a front view of the toothed rack, as well as the elliptical wheel which
engages underneath: Figure 3 shows, by an outline. the construction of the
ellipse of the moving pinion.
The form of wheel employed does not change the irregularity of the spindle
B. jointed to the moving spindle A, when it is inclined, but the desired result
is obtained by rendering the circumference of the pinion regular by unequal
radii. It is sufficient for this purpose to place the radii in accordance with
those of the square D), which serves in join the principal moving spindle A
with that make B. These mdii vary according to the inclination and the
To
position of the spindle B. thus a pinion oval form is obtained.
ascertain the oval or elliptic form required (depending on the inclination of the
spindle B) it is necessary to draw geometrically (as shown at Figure 3), an
ellipse to serve as a point of contact for a pinion of 0477 in circumference,
the inclination being 22 degrees, shown at V by a red line, the largest radius
will be about 0082. and the smallest 0'070. to obtain a regular travel, whilst

page_text: for a pinion of ordinary form equal to 0477 in circumference the radius used
up to this time with the "cardan" joint has been about 0.069 C is the fork
end of the spindle B: this fork must always be in proportion to the largest
diameter of the pinion: the part d is fitted in the slide U. the opening of
which is regulated by the inclination of the spindle B. and the width of it by
the diameter of the spindle. This slide must be firmly fixed in the principal
part of the framing, and as near as possible on the line of the centre of the
spindle A. the bearings of which are at the neck G. and at one of its
extremities. The toothed rack E has its point of contact, or "pitch line" in a
straight line, not parallel with the centre line, so as to be always at a tangent
with the "pitch line" of the pinion P. This rack is fixed by the carrying
bar X. which is itself fixed to the moveable imposing stone of the press. The
bent guide I always remains to guide the pinion above or below by means of
the roller pin g.
Another mode of obtaining the forms of the pinions consists in fixing two
plates, one of which is divided equally and placed on the spindle A, and the
other, which has to be divided at the extremity of the inclined spindle B by
turning and stopping the divided plate at each division, marked by a fixed
needle or point; these are carried again perpendicularly upon the plate, which
is not divided, and upon this plate is obtained, according to the inclination.
divisions with more or less difference between them. Lines are then drawn
from all these points towards the centre, and the form will be obtained by
means of a compass, with equal openings being applied to each of the lines
approaching the centre when the angles are obtuse, and going away from the
centre when they are more acute. Curves will then be made touching all
these points, to obtain the form of the wheel.
The construction of pinion above described offers the same advantages for
circular movement, and can be employed with a right-handed rack, being
made to rise and fall by means of an excentric, the pinion P being according
to the difference of the radii. The dimensions of the apparatus will be varied
to suit the particular purpose or mechanism to which these improvements are
applied.
In witness whereof, I, the said George Henry Birkbeck, have hereunto
set my hand and seal, this Twenty-seventh day of November, in the
year of our Lord One thousand eight hundred and sixty-one.
GEORGE HENRY BIRKBECK. (L.S.)