Improvements in Power Hammers.
Year: 1895

page_text: Date of Application, 28th May, 1895
Complete Specification Left. 28th Feb.. 1896-Accepted, 28th Mar., 1898
Date u Application, comh may,
Complete Specification Left. 28th Feb.. 1896-Accepted, 28th Mar., 1896
PROVISIONAL SPEĊIFICATION.
Improvements in Power Hammers.
I SAMUEL HEY of 56 Low Street Keighley in the County of York, Patent Agent,
do hereby declare the nature of this invention as communicated to ine from abroad
by Royal Bullard Boynton of West Townsend, Middlesex County, Massachusetts,
United States of America, Gentleman, to be as follows, that is to say:—
This invention relates to that class of power hammers in which the driving
power is transmitted to the hammer-head through the medium of compressed
air, a cylinder and piston being employed, and the hammer-head being carried by one
of said parts while the power is applied to the other. The compressed air, besides
acting as a cushion constitutes an agent which can be so controlled as to vary the
force of the stroke of the hammer-head.
The object of the invention is to simplify the means for controlling the compressed
air, and to this end the invention consists in a power hammer which comprises a
cylinder and piston, a hammer-head carried by one of said parts, means for recipro-
cating the other part, and a restricted passage affording communication from one side
of the piston to the other throughout the piston's stroke. The invention also consists
in other novel constructions and arrangements of parts hereinafter described.
The machine has an anvil, a supporting frame which has a bifurcated portion over-
hanging the anvil and its two branches having vertical slide-ways. A cylinder is
provided with grooved ribs, which engage said slide-ways, and said cylinder is extended
at the lower end to form the hammer-head. The cylinder has an open port centrally
located in one side. A piston fits the bore of the cylinder, and is carried on the end
of a tubular rod which extends through a stuffing-box in the upper end of the cylinder
and is fastened to a cross-head fitting ways on the frame. A pitman connects said
cross-head with a crank on a driving-shaft. Through these means the piston is
reciprocated.
The piston is formed with two restricted passages extending through it, and a valve
in the form of a winged plate fits against the under side of the piston and controls
said passages. The said valve is carried on the lower end of a rod which extends
through the tubular piston-rod and beyond the same through a cross-piece at the top
of the frame. A collar is supported in said cross-piece so as to turn therein, and the
valve-rod has a groove which is engaged by a feather on the said collar. An arm
projecting from the collar is connected with one arm of a bell-crank lever pivoted to
the frame and connected by a rod with a treadle. It will be seen that by depressing
the treadle the valve will be turned. The valve-rod is prevented from moving longi-
tudinally in the tubular piston-rod by a collar fastened to the valve-rod and bearing
against the upper end of the piston-rod.
In the operation of the hammer, the reciprocations of the piston impart the stroke
to the hammer-head through the air compressed between the piston and the ends of
the cylinder, the port admitting air alternately on opposite sides of the piston to
relieve the side opposite that where the compression takes place. With the passages
in the piston closed by the valve, the maximum force of the bammer is obtained.
When a lighter blow is desired, the operator, by pressing on the treadle, turns the
valve and opens the passages more or less, and the air in the cylinder will not be
compressed in the same degree as before.
It will be observed that this is a very simple construction for accomplishing the

page_text: desired end. By locating the port centrally, a check-valve is dispensed with, and the
construction thereby further simplified.
It is evident that variations may be made in the structure without departing from
the invention. For example, the arrangement could be reversed by operatively
connecting the cylinder with the reciprocating power, and rigidly connecting the
hammer with the piston, the hammer of course being then a separate part from the
cylinder.
Dated this 27th day of Mov 1805
Improvements in Power Hammers.
I, SAMUEL HEY of 56 Low Street, Keighley, in the County of York, Patent Agent,
do hereby declare the nature of this invention, as communicated to me from abroad
by Royal Bullard Boynton, of West Towsend in the County of Middlesex, and State
of Massachusetts, United States of America, Gentleman, 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 that class of power hammers in which the driving power
is transmitted to the hammer-head through the medium of compressed air, a cylinder
and piston being employed, and the hammer-head being carried by one of said parts
while the power is applied to the other. The compressed air, besides acting as a
cushion, constitutes an agent which can be so controlled as to vary the force of
the stroke of the hammer-head.
The object of this invention is to simplify the means for controlling the compressed
air, and to this end the invention consists in a power hammer which comprises a
cylinder and piston, a hammer-head carried by one of said parts, means for recipro-
cating the other part, and a restricted passage affording communication from one side
of the piston to the other throughout the piston's stroke. The invention also consists
in other novel constructions and arrangements of parts hereinafter described and
claimed.
The accompanying drawings illustrate a construction by which the invention may
be carried out.
Figure 1 shows a side elevation of the hammer.
Figure 2 shows a top plan view of the hammer.
Figure 3 shows a front elevation of the hammer.
Figure 4 shows a section on line 4-4 of Figure 3.
Figure 5 shows a bottom view of the piston."
Figure 6 shows a section on line 6-6 of Figure 3.
The same letters of reference indicate the same parts in all the figures.
In the drawings-
{
с
The letter a designates the anvil, and the supporting frame of the machine, which
has a bifurcated portion overhanging the anvil, and its two branches having vertical
slide-ways b². A cylinder c is provided with grooved ribs which engage said slide-
ways, and said cylinder is extended at the lower end to form the hammer-head c¹.
The cylinder has an open port centrally located in one side. A piston d fits the
bore of the cylinder, and is carried on the end of a tubular rod d', which extends
through a stuffing-box in the upper end of the cylinder, and is fastened to a cross-
head d fitting the ways 2. A pitman d³ connects said cross-head with a crank d
on a driving-shaft e. Through these means the piston is reciprocated.
The piston is formed with two restricted passages extending through it, and a
valve in the form of a winged plate fits against the under side of the piston
and controls said passages. The said valve is carried on the lower end of a rod f

page_text: which extends through the tubular piston-rod and beyond the same through a cross-
piece at the top of the frame b. A collar is supported in said cross-piece so as
to turn therein, and the rod has a groove f*, which is engaged by a feather f³ on
the said collar. An arm f projecting from the collar is connected with one arm
of a bell-crank lever g pivoted to the frame a and connected by a rod gl with a
treadle g. It will be seen that by depressing the treadle g the valve f' will be
turned. The valve-rod f' is prevented from moving longitudinally in the tubular
piston-rod by a collar f' fastened to the valve-rod and bearing against the upper
end of the piston-rod.
In the operation of the hammer, the reciprocations of the piston impart the stroke to
the hammer-head through the air compressed between the piston and the ends of the
cylinder, the port admitting air alternately on opposite sides of the piston to relieve
the side opposite that where the compression takes place. With the passages fin the
piston closed by the valve f¹, the maximum force of the hammer blow is obtained.
When a lighter blow is desired, the operator by pressing on the treadle ³, turns the
valve and opens the passages of more or less, and the air in the cylinder will
not be compressed in the same degree as before.
It will be observed that this is a very simple construction for accomplishing the
desired end. By locating the port centrally, as shown, a check-valve is dispensed
with, and the construction thereby further simplified.
It is evident that variations may be made in the structure shown, without departing
from the invention. For example, the arrangement could be reversed by operatively
connecting the cylinder with the reciprocating power and rigidly connecting the
hammer with the piston, the hammer of course being then a separate part from the
cylinder.
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. A power-hammer comprising in its construction a cylinder and piston, a
hammer-head carried by one of said parts, means for reciprocating the other part,
and a restricted passage affording communication from one side of the piston to
the other throughout the piston's stroke.
2. A power-hammer comprising in its construction a cylinder and piston, a
hammer-head carried by one of said parts, means for reciprocating the other part,
a restricted passage affording communication from one side of the piston to the
other throughout the piston's stroke, and a valve controlling the area of said
passage.
3. A power-hammer comprising in its construction a cylinder and piston, a
hammer-head carried by one of said parts, means for reciprocating the other part,
a restricted passage extending through the piston, and a valve adjustable to cover
said passage or to leave it uncovered throughout the piston's stroke.
4. A power-hammer comprising in its construction a cylinder having a centrally
located atmospheric port, a piston, a hammer-head carried by one of said parts,
means for reciprocating the other part, and a restricted passage affording com-
munication from one side of the piston to the other throughout the piston's stroke.
Dated this 27th day of February 1896.