Improvements in and relating to Ratchet Gearing.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Ratchet Gearing.
I, OTTO ADOLF HEINRICH RAU, of the town of Friedland in Mecklenburg in the
Empire of Germany, Engineer do hereby declare the nature of my said Invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, that is to say :-
This Invention cousists in the application of a new arrangement of parts constituting
an improved mechanical device for the purpose of transmitting continuous or inter-
mittent rotary motion to the shafts and their connections in such machines or
apparatus as windlasses, cranes, hoisting and lowering tackle, machine tools, and
numerous other mechanical appliances in which toothed gearing is now generally
employed for the said purpose of conveying or transmitting motion from the engine
or other source of motive power.
In order that the nature of my said Invention, and the manner in which the same
is to be carried into practical effect, may be clearly understood, I have annexed to this
specification a sheet of Drawings, the several Figures and letters of reference
marked thereon indicating the various details of my Invention, as hereinafter set
forth.
Fig. 1 is a diagram illustrating the relative positions of the operative parts of my
apparatus, apart from the framework in which it is supported.
Fig. 2 is a similar view, but with the addition of the standard or framework of
the apparatus.
Fig. 3 is a plan view of Fig. 2, as seen from the top thereof.
Figs. 4 and 5 represent (in side elevation and transverse section respectively) the
arrangement of an alternative formation of certain details of my Invention, as
hereinafter more fully described.
In these figures:→
The shafts, upon which ratchet wheel A is mounted, is that upon which the drum
or chain cylinder of a windlass or raising and lowering appliance would be placed (such
drum or cylinder being indicated in Figs. 2 and 3 by the letter S).
The plain wheels or rollers r., are mounted upon the spindles or axes Z Z³,
resting in bearings at the extremity of arms or cranks c. and n. One of these
arms or cranks is centred or mounted at its other end upon the main shaft s.
The pawls or spurs" a, b, upon the axes or spindles Z, Z' are in gear with the
teeth or spurs upon the ratchet wheel A.
Between the plain wheels or rollers and mounted upon spindle or axis e is the
cam or excentric E, the rotation of which determines the motion of the other parts
of the mechanism.
In Fig. 1, the dotted lines K represent the position and direction of movement
of a handle, lever, or crank, to be turned by hand or by other means, this lever
handle or crank being also represented in full in Fig. 3 by the same letter of
reference.
The arrow x. y. beside Fig. 1 showing the vertical direction, it will be understood
that the roller in that Fig. rests upon the cam or eccentric e by its own weight,
while the roller is kept pressed against the lower surface of the cam by the
influence of the counterbalance weight M', attached or fixed upon an arm or
projection at the opposite side of the boss of the double crank on axis d.
The pawl b, in connection with this double crank, is kept in gear with the spur or
ratchet-wheel by the spring bl.
The dotted lines n, n, are intended to represent the theoretical lines of force or
motion of the spur or ratchet wheel A during its rotation; these lines being drawn
from the outer circumference of the said wheel at the points where the pawls or
spurs a and b respectively come into contact with the same..

page_text: Each of these dotted lines is a tangent to the circumference of the ratchet wheel A,
and the centres of the axes or spindles Z. Z, are (upon the said dotted lines being
produced) points' in the same. The sector through which (in Fig. 1) the dotted line
or are of a circle at a is drawn, gives the dimensions of the angle formed by the
above mentioned dotted lines, and the dot and dash lines (o. o) produced from the centre
of the main shafts, which are their natural co-series, and determine with mathematical
accuracy, the exact positions to be occupied by the axes Z. Z-relatively to the axis
of the ratchet-wheel A, and consequently the position of the plain wheels or rollers r
and their adjacent and co-operating pawls or spurs a, b.
Upon giving motion to the crank lever or handle K, and through that, by spindle e,
to the cam or eccentric E, the points occupied by the centres Z Z, of the two
rollers, are simultaneously changed, with the result that the pawls or spurs a and b
are alternately thrown into and out of gear with the teeth or spurs of the ratchet or
spur wheel, giving thereby rotatory motion to the latter, which being continued,
produces the requisite uniform and continuous revolution of the shaft s, for communi-
cation to the other parts of the machinery, where such motion is to be applied to useful
purposes.
In Figs. 2 and 3, the mechanical action throughout the apparatus is as a whole-
precisely the same as above described with reference to Fig. 1. In these Figures 2
and 3, however, the axes Z Z of the two rollers r., and the intermediate axis (e) of
the cam or eccentric E, are shown to be in a horizontal line above the shaft (s) of
the ratchet-wheel S, this modification rendering the apparatus more convenient for
fixing in a framework (G) such as that of a windlass or hoisting appliance.
Where the proportions of the machine are greater than those which may be worked
by manual power, the crank or handle k at end or ends of the shaft e will of course
be substituted by an endless chain, belt, or strap, or other device connected with
motive power.
In Figs. 4 and 5, the cam is made so as to contain the wheels or rollers
its circumference, instead of exterior thereto, as in Figs. 1, 2, and 3.
within
The result of the motion of the said cam or eccentric upon the wheels, still
remains the same, and dependent entirely upon the curvature of the eccentric-
that is to say the amount of its variation froin a circle in conformation.
The cam or eccentric represented in Figs. 4 and 5, which show respectively a side
view (or plan) and transverse section, is provided or cast with a flange or projecting
part n'on one of its flat sides, this projection being indicated by the solid black surface
in the sectional view.
r
The rollers are thus contained within the circumference of the cam, and undergo
therefrom what may be properly termed a "pulling "action, as distinguished from
the pushing" action exerted upon them when situated exterior to the said cam or
eccentric, as in the other Figures previously described.
Having now particularly described and ascertained the nature and object of the
said Invention, and in what manner the same is to be performed or carried into
practical effect, 1 hereby declaro that what I claim is.
The construction and application of the improvements in and relating to ratchet
gearing, such improvements consisting in and comprising the combination of the
several parts shown in detail in the accompanying Drawings, by Figs. 1, 2, 3, 4 and 5,
and hereinbefore described with reference thereto, that is to say-The spur- or
ratchet-wheel A, pawls a, b, eccentric or cam E, rollers or wheels r, r, and
their accessories, all substantially as herein before described and illustrated by the
annexed Drawings.
1
C. R. BONNE & Co.,
Agents for the Applicant.