Improvements in Pneumatic Power Hammers.
Year: 1891

page_text: Date of Application, 4th June, 1891
Complete Specification Left, 3rd Mar., 1892-Accepted, 9th Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in Pneumatic Power Hammers.
I, HENRY BROADBENT, of Hollins Ironworks, Sowerby Bridge, in the County
of York, Engineer's Tool Maker, do hereby declare the nature of this invention to.
be as follows:-
My invention has reference to pneumatic power hammers employed for forging
metals, crushing ores and other purposes, the object of my invention being to
impart the requisite reciprocatory motion to the "tup" with either a great or
modified power. In carrying out my invention I employ a stationary pneumatic
cylinder provided with two pistons, one being attached to a rod connected to a
rotary disc, face plate or crank, and employed to pump the air. Within the other
end of the cylinder is another piston which by rod is connected to the "tup."
A suitable space or distance is left between the pistons within the cylinder for
the expansion and compression of air, and the tup is raised and lowered by the.
alternate rarefaction or expansion and compression, of the air contained within that.
space. At a point between the two pistons I employ an exhaust or check valve
for the escape of the spent air, and there is another valve which can be opened and
closed by a suitable arrangement of rods operated by a lever or treadle, the latter.
valve being employed for the purpose of allowing a slight escape of the compressed
air, which reduces the compression and thereby reduces the force of the blow given.
by the tup.
By the arrangement of a pneumatic power hammer as above described, an.
effective, durable, inexpensive, and handy machine is constructed.
Dated this 3rd day of June 1891.
TASKER & CROSSLEY,
Halifax, Agents.
COMPLETE SPECIFICATION.
Improvements in Pneumatic Power Hammers.
1, HENRY BROADBENT, of Hollins Ironworks, Sowerby Bridge, in the County
of York, Engineer's Tool Maker, 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 :-
My invention has reference to pneumatic power hammers employed for forging
and stamping metals, crushing ore, and other purposes, the object of my invention.
being to impart the requisite reciprocatory motion to the "tup," with either a great
or modified power.
In order my invention may be clearly understood, I will make reference to the.
accompanying sheets of drawings wherein
Fig. 1 is side elevation, and Fig. 2 front elevation of a pneumatic power-
hammer having my improvements applied thereto; and Fig. 3 is an enlarged section.
of my improved construction of valves.
A represents the main standard or framework of the hammer, and B a stationary
pneumatic cylinder provided with two pistons one at each end thereof. The upper-
piston is attached to connecting rod Cand is made to reciprocate vertically by
means of the crank D mounted on the main driving shaft E, such said piston being-
employed to pump the necessary air required to operate the "tup" F, which is
attached to the bottom piston rod G and works through a stuffing box H in the
bottom of the cylinder. It will be observed from dotted lines in Figs. 1 and 2,.
Di Q77

page_text: 37
that there is a certain distance or space left between the two pistons and this is
necessary for the expansion and compression of air and that the tup F is raised and
lowered by the alternate rarefaction or expansion and compression of the air
contained within that space, and effected by the reciprocatory motion of the upper
piston. At a suitable position between the two pistons, I employ an exhaust valve I
for the escape of air, which is timed to be opened when the top piston has reached
the extent of its downward stroke, thereby releasing the compressed air in the
cylinder and assisting the upward movement of the bottom piston and the "tup."
The valve I is opened at the proper time by the vertical rod J, shewn more clearly
in Fig. 1, which rod, has a slight up and down movement imparted to it by an
eccentric or cam on the driving shaft E, but if operated in a downward direction by
a cam, the said rod is raised by the spiral spring a. This reciprocating rod J presses
upon the top of the spindle of the valve 1, whereby the valve is opened and com-
pressed air allowed to escape to the atmosphere, but the said valve is immediately
closed by the spiral spring K acting underneath the said valve. In order to
reduce and lesscu or otherwise regulate the force of the blow given by the "tup" F
I employ another valve L, which is both an inlet and an exhaust valve, I may
however use two valves, one for each purpose, but I prefer to use one. This
valve Lis drawing in air during the upward movement of both pistons, but on the
downward stroke of the said pistons the valve L is used as an exhaust, for the
purpose of regulating the blow of the " tup" according to the judgment of the
workman. This valve for above purpose is opened by the operative placing his
foot upon the treadle M which causes a projection or cam on the shaft N to open
the said valve L. A spiral spring closes the said valve when the operative
removes his foot from the treadle, the spiral spring O, in this the latter valve, being
compressed against the pin P. These valves which are shewn on a larger scale in
Fig. 3 are easily adjusted and can be easily got at when required for re-grinding,
cleaning, or other purposes. in order to prevent the lower piston striking the
bottom of the cylinder, there is a suitable space left for cushioned air. Although I
have shewn that the valve L is opened by the operative placing his foot on a
treadle, the said valve may be opened by actuating a handle, but this depends on
the size and power of the hammer, and I would here observe that my improvements
may be applied either to a single or double standard hammer.
By the arrangement of a pneumatic power hammer as above described together with
valves of the construction shewn in the drawings an effective, durable, inexpensive,
and handy machine is constructed.
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 :-
Firstly. In a pneumatic hammer, the construction of the exhaust or check valve,
together with the means of operating same, substantially as described and shewn
in the drawings.
Secondly. In a pneumatic hammer, the use of a valve such as L employed for
the double purpose of inlet and outlet of air, together with means herein shewn and
described for operating same.
Thirdly. In a pneumatic hammer, the combination of a stationary cylinder, two
pistons, and the peculiar arrangement of valves, all arranged and operated in the
imanner described and shewn in the drawings.
Dated this 2nd day of March 1899
TASKER & CROSSLEY,
Halifax, Agents.