Improvements in Atmospheric or Power Hammers.
Year: 1894

page_text: Date of Application, 9th Aug., 1894-Accepted, 6th Oct., 1894
COMPLETE SPECIFICATION.
Improvements in Atmospheric or Power Hammers.
A communication from abroad by ROBERT MITCHESON REAY, of Washington
Avenue, Masillon, Ohio, Stark County, United States of America, Superin-
tendent of The Masillon Bridge Company.
I, THOMAS JAMESON, of No. 6 Warrington Road, Newcastle-upon-Tyne, in the
county of that city, Cashier, 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 has reference to an improved construction of atmospheric or power
hammer designed to combine the advantages of steam, drop and atmospheric
hammers and which, while simple in construction, is completely under the control
of the operator and so as to render it applicable to all kinds of forging, welding,
stamping, drawing, tapering, embossing and like operations.
And in order that this invention may be fully understood I will proceed to
describe the same with reference to the accompanying drawings, in which
Figs. 1, 2 and 3 are respectively front side and rear elevations, and Fig. 4 a
plan, showing an atmospheric hammer constructed according to this invention.
Fig. 5 is a central vertical section thereof, partly in elevation.
Fig. 6 is a section on the line x x of Fig. 5, looking in the direction indicated by
the arrows in that figure.
Fig. 7 is a section on the line y y of Fig. 6, looking in the direction of the arrows
in that figure.
Figs. 8 to 13 inclusive are detail-views hereinafter referred to.
The improved power hammer comprises a hammer cylinder 1 and an air pump
cylinder 2 inclined to each other and provided respectively with a hammer head 3
and a piston 4 the upper ends of the cylinders being directly connected by a short
passage controlled by a valve as hereinafter more particularly described. The
hammer head is arranged to fit the cylinder 1 in which it works after the manner
of a plunger, the said cylinder being of uniform bore throughout. The piston 4,
which serves to exhaust air from and compress air into the cylinder 1, for the
purpose of reciprocating the hammer head, is connected by a rod 5 and a crank-
pin 6 to two discs 7 which act as fly wheels. One of the discs 7 is secured on a
shaft 8 provided with fast and loose pulleys 9 and 10 respectively and carried in a
bearing 8. The other disc is carried by a pin 8 supported in the frame at 8°.
The cylinders 1 and 2 are adapted to communicate with each other by means
of two sets of ports 11 and 12. The ports 11 are forked and open into the
cylinder 1 at two places 11ª and 11 in the length thereof. The ends of the
ports 11 and 12 remote from the cylinders 1 and 2 open into a cylindrical valve.
chamber 13 in which are arranged two rotary slide valves 14 and 15 (see
Figs. 12 and 13) adapted to close the ports 11 and 12 respectively.
The valve 14 is operated by means of a spindle 16 which is connected by means
of a crank 17 and a rod 18 to a treadle 19. The valve 15 is operated by means of
a sleeve 20 which is situate on the spindle 16 and has secured on its outer end a
band regulating-lever 21.
The valve 14 is a flap valve of arc-shape in end view, as shown in Figs. 5 and 13,
and is adapted to fit the internal cylindrical surface of the valve-chamber 13.
Near one of its edges is a hole 22 (Figs. 12 and 13) with which engages one of the
prongs of a bifurcated part 23 carried by an extension 24 of a boss 25 fast on the
spindle 16 (Figs. 10 and 11), the arrangement being such that the valve can be
rocked by the spindle 16 but is free to lift to a small extent from its circular seat

page_text: when not forced thereon by compressed air, the extent of lift being limited by the
curved edge 24" of the projection 24. The valve 15 is similar to the valve 14 and
is similarly attached to and operated by the sleeve 20.
The spindle 16 and its sleeve 20 are supported in a bearing block 26 screwed
into the body of the hammer in which the inner end of the spindle 16 has a bearing
as shown. 27 and 28 are leather-washers for making air-tight joints between the
spindle 16 and sleeve and between the sleeve and block respectively. 30 is a set-
screw by which the spindle 16 can be forced end ways in a direction to compress
the said washers.
31 is a leather flap-valve adapted to permit air under pressure to issue from the
cylinder 2 through a hole 32 but to prevent air from entering therethrough.
31 is a cover or guard plate for the said flap valve.
33 is a spring bar arranged normally to keep the treadle 19 in the position shown
in the drawings.
The piston 4 is provided with a packing ring 34 that may be of cast iron as
usual. The hammer-head 3 is also furnished with packing rings 35 that may be
of metal, but are preferably of leather as this material makes a very good joint,
is not affected by shocks, wears well, and is very easily renewed. For the latter
purpose the hammer-head 3 may be lifted out of the cylinder 1 in the case of small
hammers the top of the cylinder being for this purpose made removable; or in the
- case of large hammers it will be sufficient to remove the hammer-face 36 and,
possibly, also the anvil-block 37-which should then be made detachable-to
allow the hammer head to descend sufficiently far to expose the packing grooves
therein. A single oil-hole 38 may be provided for the two cylinders and the
valve, the oil being distributed therefrom by means of the pressure and vacuum
produced in the machine. The lubricant will be prevented from dripping upon
the work by reason of the vacuum set up in the cylinder 1 at each upstroke of the
hammer head.
When it is desired to use the hammer, the driving-belt is shifted from the loose
pulley 10 to the fast pulley 9. Assuming the valves 14 and 15 to be in the
positions shown in Fig. 5, the descent of the piston 4 in the cylinder 2 will cause
air to be exhausted from the cylinder 1 through the ports 11 and will thus cause
the hammer-head 3 to be raised by the pressure thereon of the external atinosphere.
A. leather flap-valve 39 serves to prevent air being sucked from through the upper
ports 11 thereby ensuring that there shall be a cushion of air at the top of the
cylinder 1 to prevent the hammer-head 3 when rising from striking against the
cover end of the cylinder. The ascent of the piston 4 will have no effect on
the position of the hammer-head 3, as the valve 14 will, when in the position shown,
be forced on its seat and prevent air passing into the cylinder 1. In its descent
the piston 4 will pass the hole 32 and on ascending will expel therethrough a
portion of the air in the cylinder 2; by this means the partial vacuum in the
cylinder 1 will be maintained and too great a pressure prevented from being
produced in the cylinder 2. In order, now, to produce a succession of blows, the
treadle 19 is pressed down, causing the valve 14 to rise and clear the ports 11;
when the treadle is released the valve will be returned to its closed position and
the blows will cease, the hammer-head remaining in a raised position.
If it is desired merely to press down some article on the anvil, as in a vice
the valve 15 is lowered over the ports 12 by means of the hand lever 21 and
the valve 14 is slightly raised by means of the treadle 19 and when the hammer-
head reaches the article, the valve 14 is opened to the extent requisite to produce the
desired pressure.
The hammer-head can in the manner just described be lowered into any desired
position and then retained there by closing the valve 14; this operation is often
useful to level a tool to the work to be operated on before commencing to strike.
To strike a blow and prevent the hammer-head from subsequently rising, the
ports 12 are closed by the valve 15 and the treadle 19 is depressed-gradually or
suddenly according to the severity desired for the blow.

page_text: When it is desired to strike a blow of as great force as possible, the treadle is
pressed down quickly and allowed to rise at about the same time as the blow is
delivered so as to resume its initial position before the piston 4 rises again and
produces another blow.
Light blows and short strokes of the hammer-head are produced by slightly
depressing the treadle 19; and the severity of the blows and the length of the
strokes are increased as the depression of the treadle continues.
It will be seen that the hand lever 21 is rarely used and that consequently one
man is usually sufficient to hold the article to be treated and to operate the hammer.
When, however, the work required to be done is of such a nature that one man is
required to hold the article and another to operate the hammer, it is preferable to
substitute a lever for the treadle-arrangement for operating the valve 14. In some
cases the valve 15 may be omitted. Instead of constructing the hammer-head as a
piston, a separate piston may be employed and the hammer-head be suitably
secured thereto, but the former arrangement is preferred, as being simpler.
A power hammer constructed as described will be found to be particularly
adapted for architectural ironwork, bridge-building, locomotive-work, shipbuilding,
the manufacture of hardware and axes, blacksmith-work, tool-dressing of all
descriptions and general forge-work.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In an atmospheric hammer, arranging the closed ends of the hammer and air-
pump cylinders in proximity to each other and directly connecting them through
short passages of small capacity controlled by one or more valves, the arrange-
nient being such that air can be drawn direct from the hammer head into the air
pump cylinder at each suction stroke of the pump to cause the hammer head to
rise, and air can be forced direct from said pump cylinder into the hammer cylinder
at each compression stroke of the pump, to cause the hammer head to descend, so
that the hammer head will work in unison with and will promptly respond to the
movements of the pump piston substantially as herein described.
2. An atmospheric hammer of the kind specified in Claim 1, in which the
passage between the hammer and air pump cylinders is controlled by a valve
adapted to automatically lift or open to a small extent after being moved into its
closed position, so as to allow of the passage of air from the hammer cylinder
to the air pump cylinder at each suction stroke of the latter irrespective of
the position of the valve operating mechanism, substantially as hereinbefore
described.
3. An atmospheric hammer of the kind specified in Claims 1 and 2, in which
the passage of air from the air pump cylinder to the hammer cylinder is con-
trolled by a second valve adapted to automatically lift or open to a small extent
when subjected on its underside to the action of compressed air, substantially as
hereinbefore described.
4. An atmospheric hammer of the kind specified in Claim 1, in which the
air pump cylinder is provided with an outlet-valve through which excess of air
will be expelled by the air pump piston in order that the necessary vacuum will be
produced in the hammer cylinder at each suction stroke of the pump substantially
as herein described.
5. The improved atmospheric hammer coustructed arranged and operating
substantially as described and shown.
1 .
1001
W. Lloyd Wise,
THOS. JAMESON.
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.