IMPROVEMENTS IN POWER-HAMMERS FOR GOLD-BEATING MACHINES AND FOR OTHER PURPOSES
Year: 1879

page_text: LETTERS PATENT to Bristow Hunt, of Serle Street, Lincoln's Inn, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
POWER-HAMMERS FOR GOLD-BEATING MACHINES AND FOR OTHER PURPOSES."
A communication from abroad by Robert Edgar Hastings, of Philadelphia,
“Pennsylvania, in the United States of America.
* PROVISIONAL SPECIFICATION left by the said Bristow Hunt at the Office
of the Commissioners of Patents on the 19th June 1879.
BRISTOW HUNT, of Serle Street, Lincoln's Inn, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN POWER-HAMMERS FOR GOLD-BEATING MACHINES
AND FOR OTHER PURPOSES." (A communication from abroad by Robert - Edgar
Hastings, of Philadelphia, Pennsylvania, in the United States of America.)
This Invention, which relates to certain improvements in power-hammers, has
especial reference to gold-beating machines, and the main object of the Invention is
to protect the working parts of the machine from the evil effects of shocks and jars,
and to ensure the steady blows which are essential to the successful operation of
gold-beating, by such a liberal use of wood or other equivalent material in con-
structing the machine that the jars resulting from the operation of the working
parts shall be absorbed or neutralized by the cushioning influences of the material, .
the hammer in falling being thus free from tremor, and the steadiness of the blow
being further assured by the manner described hereinafter of guiding the hammer-
rod.
For the ready understanding of the present improvements I will give in the first
place a brief description of the construction and operation of the power-hammers to
which the above referred to improvements are especially applicable.
In this machine a shaft having bearings supported by a suitable frame is pro-
vided with two cranks, the pins of which are connected by rods to a cross-head
adapted to guides on the frame. A vertical rod is guided by transverse-beams of
---

page_text: the frame, the lower end of the rod being provided with a hammer-head, below
which is the anvil. The hammer head passes through the cross-head and through
an opening or recess in the same, so that the said rod and cross-head can have
vertical reciprocating movements independently of each other to an extent
determined by the play of a collar on the rod in the said opening or recess of the
cross-head.
When the hammer strikes the gold-beater's mould on the anvil it rebounds, but
before it can again strike the mould the collar is arrested by the lower portion of
the cross-head in its upward movement, and the hammer-rod is carried up until the
crank-pins on the shaft reach their most elevated position or upper dead-centres.
The downward movement of the hammer-rod is accelerated, and the violence of the
blow intensified by the upper portion of the cross-head in its descent acting on the
collar of the rod owing to the fact that the cross-head descends faster the rod can
fall by its own weight.
While this machine is made on theoretically correct principles for performing the 1
desired duty there are defects in construction which it is the object of the present
improvements to remedy,
In constructing the machine according to this Invention a pillar, preferably of
wood, is firmly secured above and below to the floors of the building in which the
machine is situated, and to opposite sides of this pillar are secured the guide-plates 1
• adapted to the reciprocating cross-head, the latter taking the place of the cross-
head in the machine above described.
"
The driving-shaft is adapted to bearings secured one to each side of the pillar,
and to this shaft is secured a balanced crank wheel. To the pin of this crank is
connected the upper end of a forked pitman or connecting rod, which is composed a
mainly of a bar of wood and of metal bars secured to each other and to the wooden
portion, the lower ends of the pitman being adapted to pins projecting from the
cross-head, one on each side of the same.
To this construction of pitman is, in a measure, due the successful operation of
the machine, as tho wooden portion tends to absorb the shocks which take place
when the crank-pin is passing its dead centres. A much steadier movement of the
slide-block is moreover assured by the combination therewith of one crank and a single
forked pitman than by the former combination of two cranks and two connecting-
rods with the cross-head. The main body of the cross-head is composed of wood,
into which are let two plates, one on each side of the cross-head, each plate carrying
one of the said pins for the lower end of the pitman, A hole somewhat larger in
diameter than the collar of the hammer-rod passes entirely through the wooden
• cross-head, which is provided at the top with a guide-plate for the rod and below
with a similar guide-plate, and within the said hole or opening are washers of
leather or other equivalent yielding material immediately below the one guide plate,
and similar washers immediately above the other guide plate, the upper washers
serving to cushion the blow which the cross-head in its descent strikes on the collar
of the hammer-rod, and the lower washers to cushion the blow which the cross-
head in its ascent strikes against the under side of the collar after the rod has
rebounded from the mould on the anvil.
For binding these guide plates to the wooden block reliance is preferably placed
on iron bands which pass up both sides of the block over the upper plate and under
the lower plate. The force of both blows on the collar of the hammer-rod is
resisted by these bands, but the wood serves to lessen the resultant jars. The good
effects of the wooden portion of the cross-head are, however, most apparent when
viewed in connection with the pitman, through the medium of which the crank
strikes the blows.
It will be seen that the metal plates carrying the cross-head pins are free from
contact with the rod guide plates, and hence that the force which is exerted through
the pitman to strike the collar of the hammer-rod must be transmitted to the latter
through the medium of a wooden cushion.

page_text: The hammer rod of the firstly described machine is guided above and below by
parts of the frame, so that any irregularity in the movement of the cross-head
tending to exert a lateral force on the hammer-bar is resisted by these bearings,
and the result is lateral tremor imparted to the rod, and the failure of the head to
strike a dead blow on the mould on the anvil. This difficulty is obviated according
to the present improvements by dispensing with the fixed guides, and relying solely
on the sliding block for the guidance of the hammer-rod.
Although these improvements are herein referred to as applied to gold-beating
hammers only they may be adopted with advantage in the construction of power-
hammers for other purposes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Bristow Hunt in the Great Seal Patent Office on the 19th
December 1879.
BRISTOW HUNT, of Serle Street, Lincoln's Inn, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN POWER-HAMMERS FOR GOLD-BEATING MACHINES
AND FOR OTHER PURPOSES." (A communication from broad by Robert Edgar
Hastings, of Philadelphia, Pennsylvania, in the United States of America.)
This Invention, which relates to certain improvements in power-hammers, has
especial reference to gold beating machines, and the main object of the Invention is to
protect the working parts of the machine from the evil effects of shocks and jars,
and to ensure the steady blows which are essential to the successful operation of
gold beating, by such a liberal use of wood or other equivalent material in con-
structing the machine that the jars resulting from the operation of the working
parts shall be absorbed or neutralized by the cushioning influences of the material,
the hammer in falling being thus free from tremor, and the steadiness of the blow
being further assured by the manner described hereinafter of guiding the hammer-
rod.
On the accompanying Sheet of Drawings Figure 1 represents a diagram of a
gold beating hammer, to which the above referred to improvements are especially
applicable; Figure 2, a side view partly in section of a machine made according to
the present improvements; Figure 3, a front view, and Figure 4 a plan view of
the reciprocating cross head.
For the ready understanding of the present improvements I will give in the first
place a brief description of the construction and operation of the device illustrated
in Figure 1.
.
In this machine a shaft A, having bearings supported by a suitable frame B, is
provided with two cranks E, the pins of which are connected by rods F to a cross-
head G, adapted to guides on the frame. A vertical rod H is guided by transverse
beams b, b', of the frame, the lower end of the rod being provided with a hammer
head d, below which is the anvil S. The hammer rod passes through the cross-
head G and through an opening or recess in the same, so that the said rod and
cross head can have vertical reciprocating movements independently of each other
to an extent determined by the play of a collar c on the rod in the said opening or
recess of the cross head.
When the hammer strikes the gold-beater's mould on the anvil it rebounds, but
before it can again strike the mould the collar is arrested by the lower portion of
the cross-head in its upward movement, and the hammer rod is carried up until the
crank-pins on the shaft reach their most elevated position or upper dead centres.
The downward movement of the hammer rod is accelerated and the violence of the
blow intensified by the upper portion y of the cross head in its descent acting on
the collar c of the rod owing to the fact that the cross head descends faster than
the rod can fall by its own weight.
While this machine is made on theoretically correct principles for performing the
desired duty there are defects in construction which it is the object of the present
improvements to remedy.
In constructing the machine according to this Invention a pillar B, see Figures 2
and 3, preferably of wood, is firmly secured above and below to the floors of the
building in which the machine is situated, and to opposite sides of this pillar are
secured the guide plates D adapted to the reciprocating cross-head G, the latter
taking the place of the cross-head in the machine above described.

page_text: The driving shaft A is adapted to bearings a, secured one to each side of the
pillar B, and to this shaft is secured a balanced crank wheel b. To the pin b² of
this crank is connected the upper end of a forked pitman or connecting rod E
which is composed mainly of a bar d of wood and of metal bars e, e', secured to
each other and to the wooden portion at the lower ends of the pitman being
adapted to pins h, projecting from the cross head G, one on each side of the same.
To this construction of pitman is in a measure due the successful operation of the
machine, as the wooden portion tends to absorb the shocks which take place when
the crank-pin is passing its dead centres. A much steadier movement of the slide
block is moreover assured by the combination therewith of one crank and a single
forked pitman than by the former combination of two cranks and two connecting-
rods with the cross-head. The main body of the cross-head G is composed of wood,
into which are let two plates i, one on each side of the cross-bead, each plate
carrying one of the pins for the lower end of the pitman. A hole m, somewhat
larger in diameter than the collare of the hammer rod H passes entirely through
the wooden cross-head, which is provided at the top with a guide-platen for the
rod and below with a similar guide plate n', and within the opening m are
washers p of leather or other equivalent yielding material, immediately below the
plate n, and similar washers pl immediately above the plate n², the upper washers
serving to cushion the blow which the cross-head in its descent strikes on the
collar c of the hammer rod, and the lower washers to cushion the blow which the
cross head in its ascent strikes against the under side of the collar after the rod has
rebounded from the mould on the anvil.
For binding the plates n, n³, to the wooden block reliance is preferably placed
on iron bands q which pass up both sides of the block over the upper plate and
under the lower plate, and are secured by screws t. The force of both blows on
the collar of the hammer rod is resisted by these bands, but the wood serves to
lessen the resultant jara. The good effects of the wooden portion of the cross-head
are, however, most apparent when viewed in connection with the pitman, through
the medium of which the crank strikes the blows.
It will be seen that the metal plates i are free from contact with the plates n, n²,
and hence that the force which is exerted through the pitman to strike the
collar of the hammer rod must be transmitted to the latter through the medium
of a wooden cushion.
On referring to the diagram, Figure 1, it will be seen that the hammer-rod of
the firstly described machine is guided above and below by parts of the frame, sO
that any irregularity in the movement of the cross-head tending to exert a
lateral force on the hammer-bar is resisted by these bearings, and the result is
lateral tremor imparted to the rod and the failure of the head to strike a dead blow
on the mould on the anvil. This difficulty is obviated according to the present
improvements by dispensing with the fixed guides and relying solely on the sliding
block for the guidance of the hammer-rod.
Although these improvements are herein referred to as applied to gold beating
hammers only, they may be adopted with advantage in the construction of power
hammers for other purposes.
Having now described the nature and object of the said Invention, together with
the manner in which the same is to be or may be performed or carried into practical
effect, I would remark in conclusion that what I claim as the Invention communi-
cated to me by the above named Robert Edgar Hastings, is-
1. The combination in a power-hammer of a reciprocating guided block or cross-
head G with the hammer rod H guided solely by the said cross-head, and having
a free vertical play to a limited extent in the same.
2. The combination of the guided block or cross-head G and the hammer-rod H,
guided by and having a free vertical play to a limited extent in the said cross-head
with the forked pitman and cranked shaft A.
3. The herein before described sliding block or cross-head composed of a body of
'

page_text: wood, the metal plates i carrying the pitman pins and the metal guide-plates n, n',
the said metal plates being isolated from each other by the intervening elastic
material.
4. The combination of the wooden body of the sliding block or cross-head G, the
metal plates n, n², and bands q; and,
5. The combination of the sliding block or cross-head, the crank shaft, and the
pitman E, composed partly of the wooden bar d and partly of the metal bars 6, €¹
Each and all substantially as hereinbefore described, and as illustrated on the
accompanying Sheet of Drawings.
In witness whereof, I, the said Bristow Hunt, have hereunto set my hand
and seal, this Nineteenth day of December, in the year of our Lord One
thousand eight hundred and seventy nine.
BRISTOW HINT (ra)