A New or Improved Mechanism for Converting Rotary into Oscillatory Motion.
Year: 1893

page_text: Date of Application, 25th Apr., 1893-Accepted, 10th June. 1893
[Communicated from abroad by SINGER MANUFACTURING COMPANY, of New
York, in the United States of America, Sewing Machine Manufacturers.]
A New or Improved Mechanism for Converting Rotary into
Oscillatory Motion.
I, ALEXANDER ANDERSON Manager of The Singer Manufacturing Company's
Works, Kilbowie, Dumbartonshire, 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 has for its object to provide a novel mechanical movement by means
of which an oscillating motion of more than 180° may be imparted to a rocking
shaft from a rotating driving shaft. To this end a crank or eccentric on the
driving shaft is connected, by a pitman, to an arm of a rocker or rocking shaft
which has a second arm having a slot and pin connection with a second rocker or
rocking shaft which in turn engages, by a slot and pin connection, a transmitter
which is connected to an arm on the shaft to be rocked or oscillated. This
transmitter is constructed with a cross head portion having a slot which is entered
by a pin or roller stud on an arm of the second rocker; said transmitter also
having flanges between which works an eccentric on the second rocker, the said
flanges being at right angles to the said slot in the transmitter so that the said
eccentric will move the transmitter laterally at the time when the pin engaging the
slot in said transmitter is passing the dead centre, thereby preventing the parts
from binding. The transmitter is also provided with an arm or guiding portion
which is received by a pivotted or swivelled guide which holds the transmitter at
all times in proper position when it is in operation.
In the accompanying drawings
Fig. 1 is a side view of an embodiment of my invention in connection with a
suitable supporting frame.
Fig. 2 is an end view of the same looking from the left of Fig. 1 and with the
framework omitted.
Fig. 3 is a view similar to Fig. 2 omitting the transmitter and its connection
with the driven shaft, for clearness of illustration, and
Fig. 4 illustrates the transmitter and its connections with the driven shaft which
are omitted from Fig. 3.
Figures 5 and 6 are detail views of the second rocker.
A denotes a rotating driving shaft provided with a crank a which is connected
by pitman B to an arm c of a bell crank lever or rocker C having a second arm c²
provided with flanges c¹ forming a groove for the reception of a roller stud d on an
arm d¹ of a second rocker or rock shaft D which has a second arm d' provided
with a roller stud d³. This second rocker D is also provided with an eccentric
herein shown as of skeleton form and consisting of the arms d the operating outer
portions of which are made in the true arc of a circle eccentric to the axis of the
said rocker D, said circle being denoted by dotted lines in Fig. 6.
E denotes a transmitter the eccentric portion or body of which is provided with
a groove e which receives the roller stud d³ of the rocker D, the said transmitter
being provided with a yoke consisting of the flanges e¹ which are at right angles to
the said groove e and between which flanges the eccentric arms d of the rocker D
are received. The transmitter E has a lower portion or arm which is connected
to an arm f of an operated rock shaft F and the said transmitter has an upwardly
extending portion or arm which is received by a pivoted or swivelled guide g
suitably mounted in the frame work H.

page_text: The operation of the invention is as follows:-
Motion being imparted to the driving shaft A the pitman B operated thereby
imparts a rocking movement to the bell crank lever or rocker C which in turn
imparts an oscillating movement to the second rocker D and the latter_causes a
reciprocating and oscillating movement to be imparted to the transmitter E, which,
in turn, is connected to the operated rocking shaft F. The pin d³ working in the
slot e of the transmitter E imparts a reciprocating movement to said transmitter,
while the skeleton eccentric, represented by the arms d working between the
flanges e¹ of the transmitter, causes a vibrating movement to be imparted to said
transmitter and thus prevents the parts from binding at the times when the
operating pin d³ on the said second rocker is passing the dead centre.
By the mechanism above described any desired oscillating movement above 180°
up to nearly a complete circle may be imparted to the operated rock shaft F, the
extent of the oscillating movements of the said rock shaft being determined by
the relative lengths of the arm c² of the bell crank lever or rocker C and the arms
of the second rocker D.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me,
declare that what I claim is :-
I
1. The combination with a rotating driving shaft provided with a suitable crank
or eccentric, and a rock shaft to be oscillated, of a bell crank lever or rocker
connected with said crank or eccentric, a second rocker provided with an arm
having a slot and pin connection with the said bell crank lever or rocker and
having also a second arm and an eccentric, and a transmitter having a slot and pin
connection with the said arm and having also flanges constituting a yoke between
which said eccentric works.
2. The combination with the driving shaft A provided with the crank a, of a
bell-crank lever or rocker C, the pitman B connecting said crank to an arm of the
said bell-crank lever or rocker, a second rocker D having the arms d¹ and d
provided with the suitable pins or roller studs d and d³ the former of which is
engaged by an arm of the said bell crank lever or rocker, said second rocker
having also the skeleton eccentric d, the transmitter E provided with the groove e
in which the said roller stud d³ works, and having the flanges el between which the
said eccentric works, the operated rock-shaft F to. which an arm or portion of the
said transmitter is connected, and a swivelled guide 9 receiving an arm of the said
transmitter and serving to steady and guide the same.
Dated this 24th day of April 1893.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.