Improved Crank Operating Mechanism for Converting Reciprocating or Alternate into Rotary Motion.
Year: 1888

page_text: Date of Application, 1st Sept., 1888
Complete Specification Left, 1st June, 1889-Accepted, 27th July, 1889
PROVISIONAL SPECIFICATION.
Improved Crank Operating Mechanism for Converting Reciprocating
or Alternate into Rotary Motion.
I, CHARLES HENRY ROSUER of 5 Westminster Chambers Victoria Street in the
city of Westminster, Civil Engineer do hereby declare the nature of this invention
to be as follows:-
My invention relates to an improved mechanism for or system of operating a pair
of cranks by means of levers to which a reciprocative motion is given. The levers
are attached to the cranks by means of connecting rods, which again are attached to
moving cogged sectors which latter are attached to the levers and work into corre-
sponding cogged sectors fixed in a suitable relative position. By this means I shorten
the stroke of the levers and overcome the dead centres through which the cranks
would have to move if operated in the usual manner.
My invention is applicable to machines or engines of every description wherein it
is desired to convert reciprocative motion into rotary motion and is partly an improve-
ment upon and extension of an invention described in the specification of Caswell
& Goslin's Patent No. 1233 of 1887 and shewn in Figure 1 of the drawings accom-
panying such specification which latter invention relates only to driving gear for
Velocipedes.
The cranks may be attached direct to the centre or spindle of a driving wheel or
pulley or such centre or spindle may be connected by means of a chain or band or by
means of cogged or friction wheels or by any other means to any other centre or
spindle for the purpose of transmitting motion to the latter and giving a higher or
lower speed or power to the latter as desired.
In the case of a Velocipede, lathe, sewing machine or the like, the initial motion would
be imparted direct to the lever by means of the foot or hand whereas in the case of a
steam, air, or gas engine the initial motion would be imparted to the lover by the
piston rod of the engine.
The improvement on the invention shewn in Figure 1 of Caswell & Goslin's
Patent No. 1233 of 1887 consists in forming each lever in two separate parts the
sectors being situated between such parts. By this means a double bearing and a
direct strain or thrust is obtained. The lower arm of the bell crank lever (D) is done
away with and its upper arm is extended to the required length.
Dated this 1st day of Sentember 1988
CHARLES H. ROSHER,
5, Westminster Chambers, Victoria Street, S.W.
COMPLETE SPECIFICATION.
Improved Crank Operating Mechanism for Converting Reciprocating
or Alternate into Rotary Motion.
I, CHARLES HENRY ROSHER, of 5, Westminster Chambers, Victoria Street, in the
City of Westminster, Civil Engineer, 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 :-
My Invention relates to crank operating mechanism for converting alternate or
reciprocating into rotary motion in such way as to diminish the stroke of the driving part
and at same time increase the mechanical advantage as well as to practically overcome
the dead centres.
My Invention is applicable to pedomotive, manumotive, or power-operated,
machinery and is in principle similar to the invention forming the subject of previous

page_text: Letters Patent granted to Caswell and Goslin, No. 1233 of 1887, and illustrated in
figure 1 of the drawings accompanying the specification of the said patent, which
relates only to velocipedes.
;
My Invention is an extension and improvement thereof, and I will proceed to
describe it with reference to the accompanying drawings forming part of this Speci-
fication, wherein figure 1 is a side elevation of a treadle-operated mechanism suitable
for a bicycle, one treadle and crank and the intervening mechanism only being shewn
Figure 2 is an edge view and figure 3 a plan of the same; Figure 4 shews a plan of
a structural modification; Figure 5 shews the application of the invention to a steam
engine. The same letters of reference indicate like parts in all the figures.
The mechanism through which the alternate motion of the treadle lever A is com-
municated to the crank C, consists of a lever B pivoted at to the lever A one end d of
this lever B being coupled by a connecting rod D to the crank pin and the other
extremity being in the form of a toothed sector E which is geared with a corre-
sponding stationary toothed sector F concentric with the centre of motion a of the
lever A.
The above described mechanism is illustrated as applied to one treadle and crank
only, but it will be understood that the opposite crank is similarly operated.
In order to give a double bearing for the centre pins at 6 and d and avoid side
strain, the arm A¹ of the lever A in which the pin b is mounted is crutched the ends
of the pin being received in eyes between which the lover B is mounted. Similarly
the end of the connecting rod D is crutched to receive the end of the lever B or
the latter might be crutched to receive the end of the connecting rod. Or, the
lover A might be made of two parallel members bolted together, as shewn in
figure 4, the lever B being mounted between the two members, the connecting rod
being jointed to it, as in figures 1 and 2. In each case, the lever A instead of being
in the form of a bell crank lever, as in the other patent before referred to, is provided
with an arm A¹.
In figure 5, the lever is straight and is formed of two parallel members bolted
together, with the above described mechanism mounted between them. This
mechanism being the same as that above described, needs no further description.
The lever A is, in this case, coupled by a connecting rod to the piston rod of an
engine.
Having now particularly described and ascertained the nature of the said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is ;
1. In the herein described mechanism for converting reciprocating or alternate into
rotary motion, the construction of lever and mode of mounting and connecting the
mechanism through which the motion of the lever is transmitted to the crank, subs-
tantially as specified.
2. The combination of the herein described mechanism for converting recipro-
cating or alternate into rotary motion with the piston of a steam or other power-
operated engine, substantially as, and for the purpose, specified.
Dated this 1st day of June 1889
Dated this 1st day of June 1889
C. H. ROSHER.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.