Improvements in Card Flat Grinding Machines.
Year: 1893

page_text: Date of Application, 11th Feb., 1893
Complete Specification Left, 11th Nov., 1893-Accepted, 16th Dec., 1893
PROVISIONAL SPECIFICATION.
Improvements in Card Flat Grinding Machines.
1 JAMES DRONSFIELD of the Firm of Dronsfield Brothers Limited, of The Atlas
Works, Oldham, in the County of Lancaster, Card Grinding Machine Makers, do
hereby declare the nature of this invention to be as follows:
My invention relates to machinery used in the grinding of the flats used in carding
engines and particularly to the cases wherein the flats are traversed to and fro in a
sideways direction and are brought into contact with a revolving grinding roller at
each traverse.
In such machines the card flats have been attached to sliding carriages which
have been actuated by means of revolving cranks or excentrics. It is obvious that
the movements imparted by cranks or excentrics will be irregular-that is to say
each movement in either direction commences and ends slowly and is constantly
varying being quickest at or near the middle of the traverse. The varying
angularity of the connecting links also affects the regularity of movement. The
work has been set up to the grinding roller by hand so that uniformity of effect has
not been obtained..
My object has been to remedy these defects.
I drive the shaft which I may term the crank shaft through an intermediate
motion consisting of a driver which is excentric with relation to a driven wheel or
part which gives motion to the crank shaft and revolves at double the speed of such
shaft.
There is a sliding connection between the driver and the driven part to allow for
the excentricity.
The amount of excentricity is calculated to be suitable to sufficiently correct the
irregularity arising from the action of the crank by speeding the crank when
passing over the dead centres and retarding the movement when passing the
66 quarter centres."
This correction may be considered to be sufficient for the purpose but I prefer to
add an additional motion to compensate for the irregularity caused by the links.
I drive the crank shaft through a driver which receives motion from the
driven wheel in the first motion and is excentric with relation to the axis of the
crank shaft.
This driver has a sliding connection with a part which is fixed upon the crank
shaft. The parts are so adjusted as that the motion of the crank shaft is accelerated
when the link ends are passing to and from the dead centre furthest from the
carriages and retarded when passing to and from the other dead centre.
When a suitable degree of excentricity has been given to the driver the carriages
will be at about the centre of their traverse when the crank pins are at quarter
centre. By the combined use of the two correcting motions I am enabled to obtain
a nearly uniform speed during the greater part of the traverse of the carriages.
This is of especial advantage when say three flats are ground at once for the
reason that with the irregular motion the two outside flats are subjected for a longer
time to the action of the grinder.
To control the grinding operation I employ a slow motion derived from the crank
shaft or from a suitable part of the machine to revolve a shaft which carries
excentrics which effect the gradual lowering of the carriage slides.
The slow motion is most conveniently obtained by means of worm and wheel
gearing. A stop or an index can be set to a fixed point or mark at the commence-
ment of the operation and the machine when started can be left for a time the flats

page_text: For
being automatically brought into nearer contact with the grinder. When the flats
have traversed to and fro a suitable number of times as arranged for the driving
belt is shifted on to the loose pulley and the action of the machine ceases.
this purpose I propose to employ a notched cam which is fixed upon the excentric
shaft and sustains in one position a swinging lever which is connected with the strap
guide bar. When the excentric shaft has revolved to the regulated extent the part
which bears upon the said can passes into the notch in the cam permitting the
swing lever to move into position to slide the strap guide bar or to permit it to slide.
A spring or load may act upon the strap guide bar or upon the swing lever or upon
a part connected with the said bar. The cam is connected with the excentric shaft
by means of a clutch or adjustable fastening so that the time of action can be varied.
I may use this automatic motion in combination with the correcting motions or
separately.
Dated this 10th day of February 1802
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.
COMPLETE SPECIFICATION.
Improvements in Card Flat Grinding Machines.
I JAMES DRONSFIELD of the Firm of Dronsfield Brothers Limited, of The Atlas
Works, Oldham, in the County of Lancaster, Card Grinding 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 and accompanying drawings
My invention relates to machinery used in the grinding of the flats used in carding
engines and particularly to the cases wherein the flats are traversed to and fro in a
sideways direction and are brought into contact with a revolving grinding roller at
each traverse.
In such machines the card flats have been attached to sliding carriages which
have been actuated by means of revolving cranks or excentrics. It is obvious that
the movements imparted by cranks or excentrics will be irregular-that is to say
each movement in either direction commences and ends slowly and is constantly
varying being quickest at or near the middle of the traverse. The varying
angularity of the connecting links also affects the regularity of movement. The
work has been set up to the grinding roller by hand so that uniformity of effect has
not been obtained.
My object has been to remedy these defects.
I drive the shaft which I may term the crank shaft through an intermediate
motion consisting of a driver which is excentric with relation to a driver wheel or
part which gives motion to the crank shaft and revolves at double the speed of such
shaft.
There is a sliding connection between the driver and the driven part to allow for
the excentricity.
The amount of excentricity is calculated to be suitable to sufficiently correct the
irregularity arising from the action of the crank by speeding the crank when
passing over the dead centres and retarding the movement when passing the
66 quarter centres."
This correction may be considered to be sufficient for the purpose but I prefer
to add an additional motion to compensate for the irregularity caused by
the links.
I drive the crank shaft through a driver which receives motion from the driven
wheel in the first motion aud is excentric with relation to the axis of the crank
shaft.
I will describe my invention more fully with reference to the accompanying

page_text: In the said drawings,
Fig. 1 represents an end elevation and
Fig. 2 a cross sectional view of the machine.
Fig. 3 is an elevation of the end of the machine which is to the right hand when
standing at the back of the machine.
In the said figs. a is the ordinary grinding roller is the crank shaft and c is the
driving shaft.
A crank disc b¹ is fixed upon one end of the shaft b and a corresponding disc b
upon the other end of the shaft and these discs carry crank pins which are
connected by links & with the two slides d d¹ to which the flats to be ground are
secured.
Previously to my invention the crank discs have had a regular motion. A
worm c¹ upon the driving shaft gears with a worm wheel fixed upon the lower end
of a vertical shafte which carries at its upper end a helical wheel e¹ which gears
with a helical wheel f.
Any other suitable combination of gearing may be used to drive the wheel f
The wheel is mounted to revolve upon a fixed circular block or stud g which is
made large enough to carry the bearing stud of a spur pinion which has an
axis which is excentric with relation to the axis of the wheel f. The method of
mounting the wheel ƒ is separately illustrated by Fig. 6 in which the said wheel
is represented in section.
In practice I have cast the part g upon the bracket g¹ which carries one end of
the crank shaft b and also carries the compensating gearing which is now being
described. A pin is fixed to the wheel and works in a block which slides in a
Blot in a carrier h' which is fixed to the wheel h.
It will be seen that as the wheel revolves the pin will carry the driver h³
around upon its bearing stud and also that in consequence of the excentric position
of the axis of the said driver the driving pin f' will by moving toward and from
the said axis communicate an irregular motion to the driver h³ and thereby to the
attached wheel h. Following the action of the parts from the positions represented
in Fig. 1 it will be seen that the pin f¹ is in its nearest position to the axis of the
wheel and that the pin 6 is at the backward "dead centre."
Whilst the wheel h
makes the next half revolution it will revolve at a gradually reduced rate. The
wheel gears with a wheel i of double the number of teeth and this larger wheel
is connected with the crank shaft b. Disregarding the compensating effects of the
motions the pins 63 would move through a quarter circle during the half revolution
of the wheel and would impart a gradually increasing speed to the carriages d d
the said speed becoming gradually less during the next quarter of a revolution.
When a suitable amount of excentricity is given to the wheel the reduction of its
velocity at one time neutralises the ordinary increase in the velocity of the said
carriages during the first quarter of a revolution of the shaft b and the increase in
the velocity of the said wheel during the other half of its revolution neutralises
the decrease in velocity of the carriages during the second quarter of a revolution
of the shaft b. This will be apparent from the fact that the wheel / would always
be moving most rapidly when the pins 63 would be passing the dead centres and
most slowly when such pins would be passing the quarter centres.
The angularity of the links is a further source of irregularity for which I
compensate. When the pins 3 would be moving toward the quarter centre the
angularity of the links would under ordinary circumstances have a retarding or
expediting effect upon the carriages so that they would not have arrived at or
would have passed the middle of their movement when the pins b³ would have
arrived at quarter centre. To neutralise this effect I mount the wheel i upon an
axis which is excentric with relation to the axis of the shaft and I establish a
sliding connection between the said wheel and the disc b¹ as in the cases of the
wheel and the driver h³.

page_text: i
The wheel is provided with a pin which works in a block which is fitted
to slide in a slot in the disc b' the slot being indicated by dotted lines in Fig. 1.
The wheel i is mounted upon a circular block or bearing piece; indicated by a
dotted circle in Fig. 1 and shown in Fig. 4 which represents the upper end of the
bracket gl. The block; has been made in a separate piece secured by screws to
the bracket as indicated for convenience of construction. It will be seen that this
block is excentric with relation to the axis of the crank shaft. The effect of this
excentricity of the driver wheel is indicated in Figure 2 wherein the circles 1
and 3 show the positions of the link end at the two ends of its stroke and the
circle 2 the central position. It will be apparent that when the link end is in the
central position the other end of the link will have passed the quarter centre into
the position 2. My object is to so proportion the excentricity of the wheel i as
that the pin shall move from the position 1 to 2 whilst the driver wheel makes a
quarter turn the next quarter turn moving the pin at a gradually reduced speed
until the other dead centre is reached.
By the combination of the two compensating motions I am enabled to obtain a
nearly uniform rate of speed of the flats whilst in contact with the grinding roller
but as hereinbefore stated the first described compensating motion might be used
without the additional motion.
This comparative uniformity of speed is of especial advantage when say three
flats are ground at once for the reason that with the irregular motion the two
outside flats are subjected for a longer time to the action of the grinder.
The front end of each of the two planed supporting bars k k¹ upon which the
carriages d slide are connected by links with excentrics m upon a rock shaft m'as in
the ordinary "Dronsfield" flat grinder and the said shaft may be operated in the usual
or in a suitable manner to raise and lower the said bars. The rear end of each bar is
sustained by means of a shaft n upon which are fixed two excentrics which work in
bearings in lugs or brackets formed upon or fixed to the bars. One of these
excentrics marked o appears in Fig. 5 which is a detail view showing the connection
of the rear end of one of the said bars with the shaft n.
As both of the bars are connected in the same manner with the shaft it follows
that if the shaft is turned in its bearings the ends of the two bars will be raised
or lowered. The excentricity of the parts o is exaggerated in the drawing.
In practice a slight excentricity is required as the use of the excentrics is to slowly
draw down the ends of the bars during the grinding of the flats. A worm p upon
the crank shaft gears with a wheel 9 and upon the same shaft as this wheel is
a second worm 9 which gears with a worm wheel r upon the shaft n. I thus obtain
a very slow motion of the said shaft the intention being that the shaft shall make
less than a complete revolution during the time required to grind the flats.
A hand levers is mounted upon a fixed stud and is jointed to the upper end of a
catch rod t which appears in Figs. 1 and 3. The lower end of this rod engages
with the sliding bar u which carries the strap fork and is acted upon by a suitable
spring which tends to move the bar in the direction which will shift the strap to
the loose pulley. So long as the bar is held by the catch rod the strap is kept upon
the fast pulley and the driving shaft c is revolved. The levers is formed
with an arms which is in position to be acted upon by a cam v fixed upon the
shaft n.
When this cam is brought round to press upon the arms the lever is slowly
turned until the lower end of the catch rod ceases to hold the strap bar and
the machine is then stopped. When commencing to grind a charge of flats the
machine is started with the rear ends of the bars k in their elevated positions the
being turned upward and away from the arm s'. The shaft m' would
be turned in the ordinary manner until the grinding of the flats would have
commenced when the machine could be left for the reason that the slow revolution
of the shaft n would gradually lower the flats so as to feed them up to the grinding
cam U
roller.
The cam v is preferably set so that by the time when the cams o would have just

page_text: passed their lower dead centre the machine would be "knocked off" by the
aforesaid action of the cam. The attendant would then raise the bars k by turning
the shaft n by hand. To enable this to be done the worm shaft q' is provided with
a handle w seen also in the detail Fig. 9. The wheel y transmits the slow motion
to the worm shaft through a pawl and ratchet wheel which permit a motion in the
same direction to be more rapidly imparted by turning the handle.
In practice I provide the worm wheel with a marked scale and apply a fixed
index seen at a in the detail Figs. 7 and 8 in order to facilitate the setting of the
parts which act to stop the machine.
If preferred the connection between the shaft n and the parts k k might be
effected by means of cams or of screws and gearing so long as both parts would be
lowered to the same extent at a suitably slow speed. Any suitable combination of
gearing may be used to impart the slow motion to the shaft n.
I do not confine myself to the use of the parts l, m and m' for the described
purpose.
The automatic feeding motion may be used in combination with the compensating
motion or motions or separately therefrom.
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.
1. The combination of parts constituting the principal parts of a card flat
grinding machine constructed and arranged to act substantially as and for the
purpose set forth and indicated.
2. Communicating motion to the crank shaft of a card flat grinding machine
through a spur pinion gearing with a wheel double its size upon or connected with
the crank shaft and having an irregular motion imparted by a wheel or part
revolving upon an axis excentric with relation to the axis of such pinion
substantially as and for the purpose set forth.
3. Communicating motion to the crank shaft of a card flat grinding machine
through a wheel or part revolving upon an axis excentric with relation to the axis
of the crank shaft substantially as and for the purpose set forth.
4. In a card flat grinding machine the wheel f, the wheel / having an axis
separated by a suitable distance from that of the wheel and the parts for
establishing a sliding connection between the two wheels in combination with
a wheel i twice the size of the wheel h for the purpose set forth.
5. In a card flat grinding machine the wheel i or a suitable driver having
its axis separated by a suitable distance from the axis of the crank shaft b and
carrying a pin working in a block sliding in a slot in the disc b' or in an
equivalent part fixed upon the crank shaft for the purpose set forth.
6. In a card flat grinding machine a shaft receiving a suitably slow revolving
motion through worm gearing or suitable gearing and connected by means of
excentrics cams or suitable parts with the bars or parts upon which the flat
carriages slide substantially as and for the purpose set forth and indicated.
7. In a card flat grinding machine the shaft provided with two excentrics which
sustain the corresponding ends of the two bars k k¹ and the worm and wheel
gearing p q q¹ and ŕ for the purpose set forth.
8. In a card flat grinding machine the parts for knocking off or releasing the
strap fork bar in combination with the automatic feed motion or with a modification
of the same substantially as set forth and indicated.
Dated this 10th day of November 1893.
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.