Improved Methods of Obtaining a Differential Temper in the Steel Pins and Card Teeth Used in Treating Fibrous Materials.
Year: 1893

page_text: Date of Application, 1st Mar., 1893
Complete Specification Left, 11th Nov., 1893-Accepted, 13th Jan., 1894
1.
PROVISIONAL STEIFICATION.
.al
Improved Methods of Obtaining a Differential Temper in the Steel
Pins and Card Teeth Used in Treating Fibrous Materials.
1, THOMAS WALTER HARDING of The Tower Works, Globe Road, Leeds in the
County of York, Engineer do hereby declare the nature of this invention to be as
follows:-
Hitherto the steel pins and card teeth used in the treatment of cotton, wool, flax,
silk etc. have been tempered in a pan or barrel in such way that the whole of the
pin or tooth has been of one temper. A differential temper-such that the point
should remain hard while the body of the pin or tooth should be pliable-is
however desirable and for certain sorts of long straight pins it has to some extent
been attained in the process, by which the roots of the pins are brought in contact
with a hot plate while being held point upward in boxes or otherwise.
This process is however only practical with long pins and is not applicable to
double teeth.
Now my invention consists in improved methods for obtaining a differential
temper in pins or teeth, so that while the body of the tooth is left sufficiently,soft,
the point may remain hard.
In my process the pins or teeth are first hardened all over in the ordinary way,
and except when it is required to have the points absolutely hard they are also
tempered in the ordinary way-say to a straw temper.
I then cause the pins or teeth to pass in succession under the action of heat,
preferably of a gas flame, so that the body becomes heated to the required.temper,
while the point is protected by contact with cold metal or water to prevent the
heat applied to the body from running up to the point beyond the distance
desired.
The carrier may be a metal plate or ring or segment or chain fitted with holes
to receive the points and maintain them in position, the carrier being kept cool by
cold water or cold air. A metal travelling band forms a convenient carrier,
especially for teeth, and the points may be kept in contact with water.
In some cases, notably for strong pins, I prefer to first temper the pins in the
ordinary way down to the temper required for the body. They are then brought
in succession under the action of heat so that the extreme points are heated to a
red heat, when by the movement of the carrier they come in contact with cold
water or oil or a stream of air.
Deted this 28th day of February 1893
Improved Methods of Obtaining a Differential Temper in the Steel.
Pins and Card Teeth Used in Treating Fibrous Materials.
I, THOMAS WALTER HARDING of The Tower Works, Globe Road, Leeds in the
County of York, Engineer do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
Hitherto the steel pins and card teeth used in the treatment of cotton, wool, flax,
silk etc. have been tempered in a pan or barrel in such way that the whole of the

page_text: pin or tooth has been of one temper. A differential temper-such that the point
should remain hard while the body of the pin or tooth should be pliable-is
however desirable, and for certain sorts of long straight pins it has to some extent.
been attained in the process by which the roots of the pins are brought in contact
with a hot plate while being held point upward in boxes or otherwise.
This process is however only practicable with long pins, is not suitable for
double teeth, and is so inefficient that it has not been in practical use for years.
Now my invention consists in improved methods-for obtaining a differential
temper in pins and teeth so that while the body of the pin or tooth is left sufficiently
soft and elastic, the point may be left as hard as may be desired. This I
accomplish by chilling the point by contact with cold metal or water or cold air
while the body is being subjected to the heat required to temper it, and the heat is
thus prevented from running up to the point except so far and to such extent as
may be desired.
In my process the pins or teeth are first hardened all over in the ordinary way
by being heated to a red heat and then plunged into oil, water or other cold
liquid.
I then cause the pins or teeth to pass in succession over the action of heat,
preferably of a gas flame, so that the body becomes heated to the blue or other
required temper, and during this process I protect the points by contact with cold
metal, water or a current of cold air.
The carrier by which the pins or teeth are successively brought over the action
of the tempering heat may vary according to the size and form of the pins or
teeth.
The simplest form of the apparatus is a circular plate or ring fitted with holes to
receive the points of the pins which are fed in by the operator during the slow
rotation of the ring. In the course of its movement the ring brings the root ends
of the pins in contact with the heat of a Bunsen or other gas burner, and the body
of the pins becomes heated to the required heat-while the heat is prevented
from spreading to the point because the points are chilled by contact with the
metal ring and could not become heated to the blue until the whole metal ring
had itself been heated to that degree. It is not found in practice necessary to
artificially cool the ring, because the heat only bears upon it during a small
portion of its course-but where necessary it may be cooled by directing a current
of cold air upon it, or letting the lower portion of it dip into water or rub against
a saturated sponge. As the ring revolves the pins drop out of the holes into a
receptacle.
Figs. 1 and 2 Sheet 1 shew a front and side view of the essential parts of such
apparatus. A is the metal ring fitted with holes-preferably on its periphery into
which the pins are put point first by the operator as shewn at B. The rotation of
the ring may be by a driving band or worm wheel or other suitable means from
the motive power. C is a Bunsen gas burner through the flame of which the pins
pass and they afterwards fall out by their own weight as they reach the lower
side D. It will be obvious that mechanical modifications such as a chain or
travelling band may be used to receive the pins into holes and so carry them past
the flame or heat. Thus, a convenient carrier, especially for double teeth is made
by using a travelling band passing over two pulleys one of which receives
suitable motion from the motive power. The teeth are put point first into a metal
plate or saddle which when filled with the teeth is placed by the operator upon
the band which carries it forward at the speed desired over a Bunsen or other
gas flame to subject the body of the tooth to the heat while the points are chilled
by contact with the metal plate. After the plate has passed the flame it is lifted
by the operator from the band and the tempered pins are emptied out from the
plate which is then refilled. In the case of double teeth I find it convenient to
use a long slit in the saddle or carrier plate and into this the double points are
readily fixed. For single pins it is more convenient to fit the plate with holes to
receive the points.

page_text: Figs. 3 and 4 shew front and side views of the essential parts of such apparatus..
A A¹ are pulleys-one of which is actuated by the motive power. B is a
travelling band upon which the carrier plates when they have been filled with.
teeth or pins are placed-the movement of the band carrying them forward so.
as to subject the body of the teeth or pins to the heat of the Bunsen gas.
burners C. D D shewn on enlarged scale at Fig. 5 are carrier plates, of which.
D is shewn partly filled with pins E E set into holes, and D' is shewn partly filled
with double teeth F F set into a slit.
In this and the form of apparatus previously described it is necessary to have
means to regulate both the heat of the gas flame and the speed of the traverse.
In regard to the gas this may be done by any of the known means, using larger
or smaller burners, a single or several burners, or a compound burner, and
regulating the supply of gas and air. The speed may be varied most conveniently
by a double cone arrangement such as is fully described further, or by other
mechanical equivalents.
The form of apparatus which I find to be most generally practical, and which.
therefore I show in detail is the following:
It consists essentially of a metal travelling band, preferably of thin steel passing
over pulleys. This band passes over a hot plate kept up to the degree of heat.
required by the action of two Bunsen gas burners. The operator spreads the pins
with the points all one way upon the band which is made long enough to allow room.
for the spreading of the pins upon the band and for levelling the points before
reaching the hot plate. As they are spread out upon the band they are carried
forward and the points are levelled by another band which acts as a travelling
gauge so that the points all project equally over the edge of the travelling band.
This latter, carrying the pins, passes over a hot plate and becoming heated
transmits the heat to the pins, the points of which are chilled by coming in contact
with a secondary band which travels alongside the hot band. This secondary band
may be a band of cotton or other material saturated or covered with water from a.
dropping tap or otherwise, or preferably I use a steel band which is kept in position
and also cooled by contact with a plate which forms part of a water tank. For the
cooling band may. be substituted a jet or jets of cold air driven upon the points and
supplied by a fan or other convenient means, but I find the cooling band to be more
efficient in its action. An essential part of the apparatus is an arrangement of
double cones for the purpose of varying the speed of traverse. I now proceed,to.
describe the apparatus in detail :-
Reference is made to the Sheet 2 of drawings forming a part of this Specification,.
in which similar letters indicate corresponding parts in each of the figures.
Figure 6 is an elevation of the machine Fig. 7 is a plan of the same.
Figs. 8 and 9 are enlarged views of details hereinafter referred to.
At A A' is a countershaft arrangement of cone pulleys of which A is driven.
from the motive power and A' communicates motion to the machine, thus enabling a
graduation of speeds to be obtained. The cone A drives the cone A' by means of
the belt A' which can be moved along the cones by suitable gear. B is a driving
pulley fastened to the shaft B and is driven from the cone gear by means of a.
belt A³. The shaft B' is carried in the headstock B. C is a pulley fastened to a
shaft B. C is a steel carrier band driven by the pulley C and passing round
the double pulley C. D is a pulley fastened to the shaft Band is connected to the:
pulley D by the belt D. D³ is a mitre wheel fastened to the same spindle as.
the pulley D'. D' is another mitre wheel gearing into D³ and connected by means of
a vertical spindle to a pulley D'. D is a steel levelling band driven by the pulley Do
and passing round the pulley D. DB is an arm pivoted on the stand E and carrying.
the pulleys D and D'. The arm E is free to move on its pivot so that the steel.
levelling band D may be made to approach to or recede from the steel carrying
band C¹. The free end of the arm E is carried on the stand F and can be
adjusted to any required. position by the set screws F F G is a steel cooling
band running parallel to the band C'driven by the double pulley C³ and passing over-

page_text: .
the pulley G'. The diameters of the driver pulleys are so proportioned. that the
three steel bands move at equal speed.. H is a fire brick furnace shewn more
particularly in the enlarged sectional views Fig. 8 and Fig. 9. Fig. 8 is a
longitudinal vertical section of one half of the furnace and Fig. 9 is a transverse
vertical section through middle of furnace. The furnace H is heated by Bunsen
gas burners H and H and is fitted with a chimney H*.
The purpose of the furnace is to heat an iron plate H over which the steel
carrier band C' passes, and to which and the pins upon it the heat is transmitted.
J is an iron tank filled with cold water which is kept cold if need be by artificial
circulation. J' is a ledge projecting from the tank J and over which the steel
cooling band G passes being kept cool by contact with it. K is the bed plate of
the machine and is supported on the standards K¹, K. L is an iron bar for
supporting the band C₁. M is an iron table fastened to the bar L. The furnace H,
the iron tank J and the support L are all carried by the bed plate K.
The mode of operation is as follows:-
The gas from the Bunsen burners H'H' is ignited and in a short time the
furnace H, the iron plate H and the portion of the carrier band C which is
passing over the plate H become heated. The cooling band G is protected from
the heat of the furnace H by means of the ledge J' which is kept cool by the
conduction of heat through the metal of the tank J and the circulation of the
water in the tank. The operator stands at the table M and lays the pins to be
tempered with the points all one way upon the carrier band C which is moving
slowly along and carries the pins towards the furnace H. The pins are laid upon
the band C with their points extending well over the edge so that they come into
contact with the inclined levelling band D. The position of the swinging arm E
has been so adjusted by means of the set screws F F that one end of the levelling
baud De is nearer to the carrier band C' than the other.
By this means, as the pins travel with the carrier band C¹, their points are
gradually pushed back to the required projection by the levelling band D. After
the pins have passed the band De their projecting points come into contact with
and lie over the cooling band G. The pins are now carried along by both the
bands G and C' with the root or thick part of the pin resting over the hot plate H*
and the points resting over the cold ledge J'. By this means the pins during their
passage over the furnace H become heated and tempered by contact with the
carrier band C¹ while their points are kept cool by contact with the cooling band G.
After leaving the furnace H the pins continue to travel with the bands G and C¹
and passing over the double pulley C they fall into a suitable receptacle placed
beneath to receive them. Large or small pins may be tempered on the same
machine by increasing or decreasing the speed at which they are carried over the
furnace so as to expose them for a longer or shorter time to the heat.
This speed is varied by moving the belt A² along the cone pulleys A A¹.
For certain pins I find it convenient to modify the machine by dispensing with
the cooling band. In this case I pass the pins over the hot plate as already
described and then subject the points only to the action of an extra Bunsen burner
so that these are raised to the red heat, and I, then chill them either by a jet of
air or cold liquid, or I cause them to drop into a receptacle containing cold liquid
so that the points which alone have been heated to the red are hardened while the
body remains of lower temper.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declure that what I
claim is :-
(1.) Producing a differential temper in the pins and card teeth used in treating
fibrous materials by cooling or chilling the point while heat is being applied to
the body.
(2.) Producing a differential temper in pins or teeth by heating the points only
to the red. and chilling them by cold air or cold liquid.

page_text: (3.) The use of carriers fitted with slits or holes to receive the points of the pins.
and card teeth so as to maintain them in contact with cold metal during the process
of tempering.
(4.) The use of a cooling band in contact with the points of pins and card teeth
while these are being carried over a hot plate or gas jets in the process of
tempering.
(5.) The use of a jet or jets of cold air directed upon the points of pins and card
teeth so as to chill the points after they have been heated to the red, or while the
body is being subjected to heat.
(6.) The apparatus substantially as described and shewn in Figs. 1-2 for
producing pins or teeth of differential temper.
(7.) The apparatus substantially as described and shewn in Figs. 3 and 4 for
producing pins or teeth of differential temper.
(8.) The apparatus substantially as described and shewn in Figs. 6, 7, 8 and 9 for
producing pins or teeth of differential temper by traversing them upon a travelling-
metal band over a hot plate or flame.
(9.) The combination of a hot plate gas furnace substantially as described and
shewn in Figs. 6 and 7 with a metal carrying band for tempering pins or teeth.
(10.) The combination of double cone driving gear or other mechanical equivalent
for obtaining differential speed with a travelling ring, chain or band for tempering
pins or teeth.
Dated this 10th day of November 1893.
T. WALTER HARDING.