An Improved Revolving Crank Motion for Making More Uniform the To and Fro Movements of a Connecting Rod or Sliding Bar.
Year: 1894

page_text: Date of Application, 27th Jan., 1894
Complete Specification Left, 27th Oct., 1894-Accepted, 1st Dec. 1894
PROVISIONAL SPECIFICATION.
An Improved Revolving Crank Motion for Making More Uniform
the To and Fro Movements of a Connecting Rod or Sliding Bar.
We THOMAS GUEST and THOMAS BROOKES of Poland Street Oldham Road
Manchester in the County of Lancaster Machine Makers do hereby declare the
nature of this invention to be as follows:-
Upon the stud or pin of a revolving crank arın we place a loose wheel or pinion,
the revolving point or centre of which we place out of the centre of the pinion-as
far as may be required-the pinion is carried round by the crank arm and revolves
on the crank pin by geering into a fixed wheel or rack containing double the
number of teeth that is in the pinion and of such a shape that the pinion is
constantly in geer with the rack or wheel so that when the shortest radius of the
pinion is in geer with the rack wheel, the pinion revolves at a proportional quicker
speed than when the longest radius is in geer.
To this pinion we attach another crank arm which works the connecting rod or
sliding bar and so arranged that when the crank pin is passing the centre the
shortest radius of the pinion is geering with the rack wheel and carries the crank
pin quickly over the centre, and the different radii of the pinion geering into the
rack wheel as it revolves gives a varying speed to the pinion and its crank arm,
thus making more uniform or equalizing the to and fro, or up and down motion of
the sliding bar.
The wheel or rack may have its teeth made internal or external, the pinion
working outside or inside the rack wheel accordingly.
Dated this 21th dor of Lan 1901
PETER
MCGREGOR,
Norwood Road, Southport, Agent for Applicants.
COMPLETE SPECIFICATION.
An Improved Revolving Crank Motion for Making More Uniform
the To and Fro Movements of a Connecting Rod or Sliding Bar.
We, THOMAS GUEST and THOMAS BROOKES, of Phoenix Iron Works, Poland
Street, Manchester, in the County of Lancaster, Machine Makers, 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 is designed to provide an arrangement and combination of
mechanism whereby a more uniform reciprocating movement-not quicker at one
part of the stroke than another-can be obtained or transmitted from a rotating
shaft or spindle.
It is suitable to be applied where a quick traverse motion is required, and is
intended primarily for winding frames for winding yarn into rolls on bobbins or
tubes without ends or heads, it may however also be applied to the traverse rail
of thread guides for spinning and winding frames, to pump rods, or to other
machines where it is desirable to overcome the unequal movement of the crank.
It consists essentially in applying to the crank pin or stud of the ordinary
revolving crank arm or disc a loose wheel or pinion bored eccentrically and gearing
into a fixed wheel or rack by which it is caused to rotate on the crank pin, the
Pain Q1

page_text: Fig. 2. plan.
Fig. 3. sectional elevation of modified form of pinion and rack.
Fig. 4. plan.
A crank arm or disc A with a crank pin B is keyed to the rotating shaft or
spindle C and receives motion therefrom. On the crank pin B of the revolving
crank arm or disc A eccentrically we place a loose wheel or pinion D which is
free to rotate on the pin B. The pinion D is bored eccentrically and the pivot
about which it rotates is placed as far out of the centre as may be found desirable.
The pinion D is carried round by the crank arm or disc A as it rotates about the
shaft C and in addition it is caused to rotate npon the crank pin B by a fixed
wheel or rack E with which it gears. The wheel or rack E is preferably provided
with internal teeth with which the pinion D gears the number of teeth in the
rack E being double that in the pinion D. The rack E is of such a shape (as
shown) that the pinion D is constantly in gear with it the shortest radius of the
pinion being in gear when the crank is on the dead centres and the longest radius
being in gear when the crank pin is furthest removed from the dead centres.
When the shortest radius of the pinion D is in gear with the rack or wheel E
it is caused to rotate much more quickly than when the longest radius is in gear
hence the slowness of the traversing movement of the crank pin when passing over
the dead centre is compensated for by the greater speed of the pinion D and the
gradual increasing movement of the crank corresponds with the decreasing speed
of the pinion so that an almost uniform movement is obtained.
To the pinion D is attached another crank arm F by which the movement of
the pinion is transmitted to connecting rod or sliding bar H by which it is
connected to the machine or mechanism to be operated. The pin G in the crank
arm works in the slot h' of the cross bar or cross head h attached to the
connecting rod or rods H.
Referring to Figs. 3 and 4 a modified construction is illustrated in which pins
instead of ordinary teeth are employed in the rack or wheel E. The teeth will be
inserted between two plates of the desired shape.
Instead of a toothed wheel D and toothed wheel or rack E the wheel D and the
fixed wheel E may have a frictional contact only, each being coated or covered
with leather, rubber, or other suitable material.
The wheel or rack instead of being constructed with internal teeth as shown may
be made with external teeth the contour being so altered that the pinion D working
outside will always gear with it. In this case it will be desirable to provide a
boss or hub on the pinion and a groove outside the teeth of the rack into which
the boss fits to guide it in its path round the rack.
The crank arm F and connecting rod H are so arranged that when the crank
pin B is passing the centre the shortest radius of the pinion D is gearing with the
rack or wheel E and carries the crank pin quickly over the centre and the different
radii of the pinion as it rotates gearing into the rack gives a varying speed to the
pinion D and its crank arm F thus making more uniform or equalizing the
reciprocating movement of the connecting rod or sliding bar H.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1. A crank motion by which a more uniform reciprocating movement can be
transmitted from a rotating shaft to a connecting rod or bar, constructed with a

page_text: wheel or pinion mounted eccentrically to rotate on the pin of a crank arm or disc
gearing with a rack or wheel so shaped that the shortest radius of the pinion is in
gear when the crank is ou the dead centres and carrying a second crank arm to
connect with the connecting rod substantially as described.
2. In a crank motion the combination with the crank arm or disc of an eccentric
wheel or pinion placed to rotate on the crank pin, a fixed wheel or rack with which
the pinion gears and by which it is caused to rotate on its axis, and a second
crank arm attached to the loose wheel or pinion substantially as and for the
purpose described.
Dated this 26th day of October 1894.
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.