IMPROVED MECHANISM FOR CONVERTING CIRCULAR INTO RECIPROCATING MOTION AND VICE-VERSÂ
Year: 1885

page_text: We FREDERICK FOULSTON Clerk and ARTHUR FOULSTON Cabinet Maker both of
126 St Lukes Road Birmingham in the County of Warwick do hereby declare the
nature of our Invention for IMPROVED MECHANISM FOR CONVERTING CIRCULAR INTO
RECIPROCATING MOTION AND VICE-VERSÂ to be as follows:-
Our invention consists of a cylindrical piece of metal or other suitable material
having two similar helical grooves cut upon it, the one right handed and the other
left handed. These helical grooves unite at each end so as to foria an endless
helical groove. The cylindrical piece is prolonged at each end beyond the screwed
part-Either the same or a different diameter for the purpose of forming bearings
or of attaching wheels or other parts embracing the screwed part of the aforesaid
cylindrical piece is a cap or box made in two halves and bolted together-On the
inside of one half of the cap or box is fitted a shuttle shaped piece, in form corre-
sponding to that of the cylinder and its groove, and of length about one third the
circumference of the cylinder. This has a partial rotating rotary motion on a pin at
right angles to that of the screwed cylinder. The pin carrying this shuttle shaped piece
passes through the half cap or box and is pressed down by a spring on the outside-
On the inside of the same part of the cap or box is a cross bevel slot to act as a
guide to the shuttle shaped piece which with the cap or box acts the part of a uut.
On giving a rotating motion to the screwed cylinder by any appropriate means
the cap or box traverses along the screw in the direction of its length to the end of
the screw or helical groove, upon reaching which the position of the shuttle shaped
piece in the cap is reversed by the turn in the helical groove of the cylindrical
piece, the spring outside the cap pressing the pin holding the shuttle shaped piece
down lower into the screwed groove which is here cut deeper than the other part
for this purpose.
This allows the shuttle shaped piece to come out of the one slot and pass into the
other putting it into position for the return motion.
By continuing the rotary motion of the screw in the same direction the cap or
box now moves back along it and this may be continued as long as desired, the
otary motion of the screw causing a to and fro movement of the said cap or box,
TD 0/1

page_text: The cap or box must be suitably guided so as not to partake of the rotary
motion of the screw.
The screw may work upon conical centres at each end, or in any suitable form of
bearing and to the outside of the cap or box may be affixed a lever or crank or any
portion of the machinery which is to have such a motion as that given by this
invention.
This invention is applicable to all kinds of mechanism where speed power or
quick reversion is required.
We FREDERICK FOULSTON, Clerk, and ARTHUR FOULSTON, Cabinet Maker, both
of 126 St Lukes Road, Birmingham in the County of Warwick do hereby declare
the nature of our invention for "IMPROVED MECHANISM FOR CONVERTING CIRCULAR
INTO RECIPROCATING MOTION AND VICE-VERSÂ" and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
Our invention consists of a cylindrical piece of metal or other suitable material
having two similar helical grooves cut upon it, the one right handed, and the other
left, handed. These helical grooves unite at each end, so as to form au endless
helical groove. The cylindrical piece is prolonged at each end beyond the screwed
part, either the same or a different diameter for the purpose of forming bearings or
of attaching wheels or other parts. Embracing the screwed part of the aforesaid
cylindrical piece is a cap or box made in two halves and bolted together. On the
inside of one half of the cap or box is fitted a shuttle shaped piece, in form corres-
sponding to that of the cylinder and its groove, and of length about one third the
circumference of the cylinder. This has a partial rotary motion on a pin at right
angles to that of the screwed cylinder. The pin carrying this shuttle shaped piece
passes through the half cap or box and is pressed down by a spring on the outside.
On the inside of the same part of the cap or box is a cross bevil slot to act as a guide
to the shuttle shaped piece which with the cap or box acts the part of a nut.
On giving a rotating motion to the screwed cylinder by any appropriate means
the cap or box traverses along the screw in the direction of its length to the end of
the screw or helical groove, upon reaching which the position of the shuttle shaped
piece in the cap is reversed by the turn in the helical groove of the cylindrical

page_text: piece the spring outside the cap pressing the pin holding the shuttle shaped piece
down lower into the screwed groove which is here cut deeper than the other part
for this purpose. This allows the shuttle shaped piece to come out of the one slot
and pass into the other putting it in position for the return motion.
By continuing the rotary motion of the screw in the same direction, the cap or
box now moves back along it, and this may be continued as long as desired, the
rotary motion of the screw causing a to and fro movement of the said cap or box.
The cap or box must be suitably guided so as not to partake of the rotary motion
of the screw.
The screw may work upon conical centres at each end, or in any suitable form
of bearing, and to the outside of the cap or box may be affixed a lever or crank or
any portion of the machinery which is to have such a motion as that given by this
invention.
This invention is applicable to all kinds of mechanism where speed power or
quick reversion is required.
And in order that our said invention may be more clearly understood we have
prepared the accompanying sheet of drawings by the aid of which we will proceed
more particularly to describe it.
Similar letters of reference denote similar parts in every figure where they occur.
Fig. 1 is a front view of our invention as applied in connection with a tricycle.
Fig. 2, is a side elevation of same.
Fig. 3, is the cylindrical piece with right and left handed helical groove
detached.
Fig. 4, is the half cap or box with cross bevil slot, shuttle shaped piece and
spring, in side and front elevations.
Fig. 5, is a half cap or box with shuttle shaped piece of modified formed back,
in side and front elevations.
Fig. 6, is a side and front elevation of shuttle shaped piece of the modified form
as shewn in Fig. 5 but detached.
Fig. 7, shews the application of our invention to a tricycle in side and front
elevation to a smaller scale.
The cylindrical piece a has two helical grooves similar except that one is right.
and the other left handed cut upon it as shewn at a¹, a¹. These grooves are
united at each end so that they form a continuous helical groove, and at the ends
where they unite the grooves are cut deeper as shewn at a, a², when the form of
box and shuttle piece shewn in Fig. 4 is used, but when the form as shewn in
Figs. 5 and 6 is used, then the grooves are not deepened at a², a², but are as shewn
by the dotted lines at those places. The cylindrical piece a has projecting bearing
pieces a³, a³, which may also project if required to receive wheels or other parts
that may require to be attached, b, is a framing supporting the helically grooved
piece a, it has a projecting loop b¹ carrying bearings b², 62, it has also suitably
formed guides 63, 63 parallel to the axis of the cylindrically shaped piece a, it has
also suitably formed bearings 6, 64 to receive the ends of the cylindrical piece a
(when applied to a tricycle the framing 6 is screwed to the framing of tricycle)
c, c, are half caps or boxes which slide backwards and forwards between the
guides b³ and one of which is placed on each side of the cylindrical piece a. These
half caps have each a semi-circular recess c¹ (Figs. 4 and 5) to clear the surface of
the piece a, each is also provided with a projection c³, c, to suit the guides 63 6³,
the outer side of each box is or may be provided with a circular projection c³, c³,
(Figs. 1 and 5) for a purpose hereafter described. The half box or cap c (Fig. 4)
is provided with a cross bevil slot, c', and a small circular hole c³, and spring c
d, d, are shuttle shaped pieces one of which is placed in each of the half boxes c, c,
so that when the half boxes are in their working positions as shewn in Figs. 1
and 2, the shuttle shaped pieces engage in the helical grooves a¹ a¹, in the
piece a. e. Fig. 2 is an axis to which are secured two cranks ff (Figs. 1 and 2)
these cranks are placed one in advance a little of the other as shewn in Fig. 2.
they are provided with crank pins f'f' each of which has a small circular motion

page_text: round the centre f' of the crank pin boss f³. The cranks ff are connected with.
the projections c3 c on the half boxes c by means of the connecting rods g. 9
on the axis e is secured the spur wheel h, which gears into the spur wheel ; and
thereby communicates motion to the driving axle of the tricycle, or to any other
required mechanism.
5
In the application to a tricycle circular motion is communicated to the helically
grooved piece a through a bevil pinion k, which is mounted on the projecting
picce as, rotary motion is given to the bevil pinion by the bevil wheel Z, which
gears into it. The bevil wheel is secured to the pedal crank axle m, which is
carried in a central. bearing attached to the frame of the tricycle and not shewn on 1
the drawing. n. n are the cranks, and o, o, are the pedals (see Fig. 1). p, is a
driving wheel and q the axle of the tricycle (Fig. 7).
The action of the apparatus is as follows, rotary motion being given by the
means described or in other convenient manner to the helically grooved piece a, the
shuttle shaped pieces d, d, in the half caps or boxes c, c,. will act as a nut in one of
the helical grooves (say the right handed one) of the piece a these being guided by
the grooves 63, 63, in the framing b, they are forced to travel along in a direction
parallel to the axis of a; when each shuttle shaped piece d comes to the end of the
groove it drops into the deeper portion of the groove a³ (Fig. 3) and takes a fresh
position corresponding with the helical groove of the other hand into which it now
enters being allowed to do so by the cross bevil slot c (Fig. 4) which acts as a
guide The spring c acting on the projection d³, at the back of the shuttle shaped
piece d allows it to do this.
"
Fig. 6, is a circular projection at the back of the shuttle shaped piece d, which
fits into a corresponding circular recess c7 (Fig. 5), which is another means we may
adopt to secure the same object, and in adopting this modified method the helical
groove at al on the cylindrical piece a does not require to be made deeper than
the remaining part of the said groove and the cross bevil slot c* (Fig. 4) and
spring c (Fig. 4) are also not required.
It will be observed that the boxes c, c, usually move in the same direction as
each other but when they are near either end of the helical groove one will for a
short time be moving in a contrary direction to the other. It will be seen from
what has been said and from an inspection of the drawings that so long as
continuous circular motion is given to the cylindrical piece a so long will the half
boxes move to and fro in the framing b.
In converting the reciprocating movement of the half boxes c. c into continuous
circular motion of theaxle e, and wheel h, take advantage of the fact that one of
the half boxes c, is a little in advance of the other and place the cranks f. f.
correspondingly so that both shall not be at the dead point at the same time, to aid
in effecting this object the crank pins f¹, f1 are placed in the manner previously
described, but in machinery where a fly wheel can be used the cranks f,f, may be
placed in position directly opposite one another as in ordinary machinery and the
shuttle caps and connecting rods arranged accordingly (that is to say) one shuttle
in the one handed groove and the other shuttle in the other handed groove.
We are not aware that a cylinder with a right and left handed helical groove
has been used to convert circular into reciprocating motion. We do not confine
ourselves absolutely to the exact shape configuration or combination of parts shewn
on the accompanying drawings or described in this Specification but hold ourselves
at liberty to vary them while not departing essentially from the said invention.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
1st The construction of a cylindrical piece having a right and left handed
continuous helical groove, with those parts of the groove at each end made deeper
than the rest, or not as the case may be for the purpose hereinbefore described.

page_text: 2nd The combination of half caps or boxes each (and not one only) having a
cross bevil slot to act as a guide to the reversal of movement of the shuttle shaped
pieces which engage in the helical groove, or without such slots as before mentioned
in the case of the modified method Figs. 5 and 6.
3rd The combination of a projection on the back of each shuttle shaped piece
with a spring to facilitate its reversal of motion in the cross bevil slot before
described or without such combination or spring as before mentioned in the case of
the modified method (Figs. 5 and 6).
4th The combination of two cranks one in advance of the other with their
eccentrically placed crank pins, and the connecting rods as described for the
purpose of reconverting the reciprocating motion into circular.
5th The application of our said invention as described or any mere modification
thereof to the propulsion of tricycles or similar vehicles.
6th The application of our said invention as previously described or any mere
modification thereof to all other pieces of mechanism where the same would be
convenient and useful.