Improved Mechanism for Converting Reciprocating Motion into Rotary Motion and Rotary Motion into Reciprocating Motion.
Year: 1893

page_text: Date of Application, 5th Apr., 1893
Complete Specification Left. 21st Dec., 1893-Accepted, 17th Mar.. 1894
PROVISIONAL SPECIFICATION.
Improved Mechanism for Converting Reciprocating Motion into
Rotary Motion and Rotary Motion into Reciprocating Motion.
I, GEORGE HUMPHRIES, of 28 Richmond Road, Barnsbury, in the County of
Middlesex, Wood Carver, do hereby declare the nature of this invention to be, as
follows:-
This invention relates to improvements in mechanism for converting reciprocating
motion into rotary motion and rotary motion into reciprocating motion whereby
the disadvantages of the varying leverage of crank mechanism is avoided.
According to this invention I place upon the shaft or spindle to be rotated
a toothed sector of about 150 degrees or rather less than a semi-circle. On
each side of the shaft is arranged a rack having the same number of teeth as
the sector with which the two racks alternately engage the one on the forward
and the other on the backward stroke. These racks are connected by end pieces
so as to form a rectangular frame around the sector. It is to this frame that
the rectangular motion is given. When the parts are in such a position that
the last tooth of the sector engages with the last recess in one of the said racks the
other rack will not engage with the sector by 'reason of the latter not having
teeth on more than about 150 degrees of its periphery. It will be readily seen that
the frame may be moved along in the direction to rotate the sector until it comes
to the last tooth of the latter when notwithstanding the continued movement of the
frame it will remain stationary by reason of there being no more teeth to engage.
Any return movement given to the frame will result in the reversal of the move-
ment of the sector which has not been rotated sufficiently in the first direction to
come into gear with the other rack by means of which, to give such additional
movement to the sector that will bring it into gear with the other rack I employ
the following mechanism :-
To the face of the sector I attach a cross piece extending across its centre, the
two ends of which extend to the periphery of the sector at diametrically opposite
points lying beyond the portion occupied by the teeth. These projecting ends
may for the purpose of explanation be regarded as additional teeth completing
the semi-circle but lying in another plane to that occupied by the teeth already
described.
On the side of the cross piece farthest from the toothed edge of the sector are
two projecting teeth placed at equal distances from the centre of the cross piece.
These engage (when the rectangular frame is at the end of its stroke) with two
correspondingly shaped depressions formed in the side of a rocking bar pivoted
centrally at each end of the rectangular frame. The ends of the said rocking bars
are extended inwards so as to embrace the cross bar secured to the surface of the
sector when the rectangular frame is at the end of its stroke. A spring is applied
to each of the rocking bars so as to maintain them in such a position that one of
the inwardly projecting ends of each rocking bar is directed inwards towards the
sector. The end that is so pressed in is that farthest from the rack that is
engaging with the sector as when the frame nears the end of its stroke towards the
rocking bar. As the frame completes its stroke the said inwardly projecting arm
and one end of the cross bar carried by the sector come in contact with one
another-the inwardly projecting arm moving towards the sector with the
rectangular frame and the end of the cross bar on the sector approaching the said
arm by reason of its movement about the centre upon which the sector turns. The

page_text: continued movement of these parts presses the inwardly projecting arm outwards
and so rocks the rocking bar of which it forms part upon its pivot and brings the
recesses into position to receive the teeth formed upon the cross bar carried by the
sector. Before these parts engage with one another the opposite end of the cross
bar upon the sector comes into engagement with the inner side of the angle formed
by the junction of the outer end of the rocking bar with its inwardly bend end.
At the end of the stroke the cross piece upon the sector lies at right angles to the
path of the rectangular frame and close to the inner side of the rocking bar
between the bent ends of the same which are sufficiently wide apart at their
base to accommodate the cross piece on the sector. These ends incline inwards
however to engage with the ends of the cross piece on the sector in the manner
described. At the end of the stroke the cross bar on the sector does not lie
centrally with the rocking bar on the frame by reason of the pressure of the
spring on the latter which keeps its inner angle in engagement with one end of the
cross bar on the sector at the side farthest from the rack that was in engagement
with the sector during the last stroke. On the return of the rectangular frame this
engagement causes the cross bar on the sector to rock upon its pivot, turning with
it, the sector which is thus brought into engagement with the first tooth of the
rack opposite that one which was in engagement during the previous stroke.
From the foregoing description it will be seen that the sector engages alternately
with each rack so that the direction of its rotation is unchanged. This is of course
only the case when the reciprocating frame accomplishes the full extent of its
stroke. Otherwise the sector remains in engagement with one rack and consequently
oscillates upon its centre.
Dated thin 8th don of A 1002
CASTLE SMITH,
Invention" Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improved Mechanism for Converting Reciprocating Motion into
Rotary Motion and Rotary Motion into Reciprocating Motion.
I, GEORGE HUMPHRIES, of 28 Richmond Road, Barnsbury, in the County of
Middlesex, Wood Carver, 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 :-
This invention relates to improvements in mechanism for converting reciprocating
motion into rotary motion and rotary motion into reciprocating motion whereby the
disadvantage of the varying leverage of crank mechanism is avoided.
According to this invention I place upon the shaft or spindle to be rotated a
toothed sector of about 150 degrees or rather less than a semi-circle. On each side
of the shaft is arranged a rack having the same number of teeth as the sector with
which the two racks alternately engage, the one on the forward and the other on
the backward stroke. These racks are connected by end pieces so as to form a
rectangular frame around the sector. It is to this frame that the rectangular
motion is given. When the parts are in such a position that the last tooth of the
sector engages with the last recess in one of the said racks the other rack will not
engage with the sector by reason of the latter not having teeth on more than about
150 degrees of its periphery. It will be readily seen that the frame may be moved
along in the direction to rotate the sector until it comes to the last tooth of the
latter when notwithstanding the continued movement of the frame it will remain
stationary by reason of there being no more teeth to engage. Any return move-
ment given to the frame will result in the reversal of the movement of the sector

page_text: which has not been rotated sufficiently in the first direction to come into gear with
the other rack by means of which, to give such additional movement to the sector
that will bring it into gear with the other rack I employ the following
mechanism :-
To the face of the sector I attach a cross piece extending across its centre, the
two ends of which extend to the periphery of the sector at diametrically opposite
points lying beyond the portion occupied by the teeth. These projecting ends, may
for the purpose of explanation be regarded as additional teeth completing the semi-
circle but lying in another plane to that occupied by the teeth already described.
On the side of the cross piece farthest from the toothed edge of the sector are
two projecting teeth placed at equal distances from the centre of the cross piece.
These engage (when the rectangular frame is at the end of its stroke) with two
correspondingly shaped depressions formed in the side of a rocking bar pivoted
centrally at each end of the rectangular frame. The ends of the said rocking bars
are extended inwards so as to embrace the cross bar secured to the surface of the
sector when the rectangular frame is at the end of its stroke. As the frame
completes its stroke one of the said inwardly projecting arms and one end of the
cross bar carried by the sector come in contact with one another, the inwardly
projecting arm moving towards the sector with the rectangular frame and the end
of the cross bar on the sector approaching the said arm by reason of its movement
about the centre upon which the sector turns. The continued movement of these
parts presses the inwardly projecting arm outwards and so rocks the rocking bar of
which it forms part upon its pivot and brings the recesses into position to receive
the teeth formed upon the cross bar carried by the sector. Before these parts
engage with one another the opposite end of the cross bar upon the sector comes
into engagement with the inner side of the angle formed by the junction of the
other end of the rocking bar with its inwardly bent end. At the end of the stroke
the cross piece upon the sector lies at right angles to the path of the rectangular
frame and close to the inner side of the rocking bar between the bent ends of the
same which are sufficiently wide apart at their base to accommodate the cross piece
on the sector. These ends incline inwards however to engage with the ends of the
cross piece on the sector in the manner described. On the return of the rectangular
frame, as the end of the cross bar on the sector at the side farthest from the rack
that was in engagement with the sector during the last stroke, is still in engagement
with the inner angle of the rocking bar and this has been thrown to one side by the
sudden gearing of its teeth with those of the cross bar on the sector the sector is
revolved and is thus brought into engagement with the first tooth of the rack
opposite that one which was in engagement during the previous stroke.
From the foregoing description it will be seen that the sector engages alternately
with each rack so that the direction of its rotation is unchanged. This is of course
only the case when the reciprocating frame accomplishes the full extent of its stroke,
otherwise the sector remains in engagement with one rack and consequently
oscillates upon its centre.
And in order that my invention may be more fully understood and carried into
practice, I will now proceed to describe the same with reference to the accompanying
drawings of which Fig. 1 is a front elevation, Fig. 2 a section on line 2-y, and
Fig. 3 a front elevation of a modified manner of applying my improved mechanism.
On the shaft a to be rotated is a toothed sector 6 of about 150 degrees or rather
less than a semi-circle. On each side of shaft a is arranged a rack c' having the
same number of teeth as the sector with which said two racks alternately engage,
one on the forward and the other on the backward stroke. These racks c¹ are
connected by end pieces so as to form a rectangular frame e to which the recipro-
cating motion is given.
When the parts are in such position that the last tooth of the sector 6 engages
with the last recess in one of the racks c' the other rack will not engage with the
sector until the latter has been slightly revolved, so that any movement given to the
frame in an opposite direction to that in which it had been previously travelling

page_text: will result in the reversal of the movement of the sector. To give such additional
movement to the sector as will bring it into gear with the other rack, I employ the
following mechanism :-
To the face of the sector 6 I attach a cross piece d the opposite ends d³ of which
extend to the periphery of the sector at points lying beyond the portion occupied
by the teeth, and may be regarded as additional teeth completing the semi-circle
although in another plane to those of the sector.
On the side of the cross piece d furthest from the teeth of the sector b are formed
two projecting teeth d² situated at an equal distance from the centre of cross.
piece d, and which engage (when the frame c is at the end of its stroke) with
corresponding depressions in the side of a bar e one of which is pivoted at each end
of the frame c and has its ends e¹ turned inwards so as to embrace the cross piece d
when frame c is at the end of its stroke.
As the frame c nears the end of its stroke one end e¹ of bar e engages with that
end d' of cross piece d which is farthest in advance, so rocking the bar e sufficiently
to allow the teeth d² to engage with the corresponding recesses in the bar e, when
by the sudden gearing together of such teeth the rocking bar e is thrown slightly
to one side.
Thus on the return stroke, as that end of the cross bar d farthest from the rack
that was in engagement with the sector during the last stroke, is still in engagement
with one of the parts e¹ of the bar e, the sector is sufficiently revolved to bring its
first tooth into engagement with the opposite rack.
Stops are provided to regulate the movement of the rocking bars e.
It will thus be seen that the sector engages alternately with each rack, when
the frame accomplishes its full stroke, so that the direction of its rotation is
unchanged.
g
In Fig. 3 the above mechanism is used to operate by pendulum 9 the rack in this
case being formed in the opposite curved faces of an opening in the lower end of
said pendulum.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
Mechanism for converting reciprocating motion into rotary motion and rotary
motion into reciprocating motion, substantially as and for the purpose hereinbefore
set forth and described and illustrated in the accompanying drawings.
Dated this 16th day of December 1893.
66
CASTLE SMITH,
Invention "Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.