IMPROVED PERCUSSION TOOL FOR VARIOUS USES
Year: 1884

page_text: AN
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Win. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of
Patent Agents, do hereby declare the nature of the said Invention for "
IMPROVED PERCUSSION TOOL FOR VARIOUS USES" and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :--
This Invention is designed more especially for adapting compressed air to be used
as the motive force in drilling and dressing stone, caulking vessels, chasing and
engraving metal, and for various other purposes where a reciprocating tool is
required, and the invention consists of a tool or apparatus wherein a piston or
striker is employed that will be rapidly reciprocated and caused to deliver blows
upon a tool carrying spindle by a current of air forced into or through the device
or apparatus.
The invention consists also in a transversely arranged valve fitted in the piston
or striker that automatically opens and closes air ports to admit air above and
below the striker and permits the entrance of air to and its exhaust from tho
apparatus.
The invention further consists of the arrangement of the air ports and the
general construction of the apparatus and in forming the inner end of the tool
carrying spindle with, an enlarged head to increase the effectiveness of the blows of
the piston or striker, also in grooving the lower end of the piston or striker to
facilitate the exhaust of air from below the piston or striker..
Reference is to be had to the accompanying drawings forming part of this
specification in which similar letters of reference indicate corresponding parts in all
the figures.
Figure 1 shows the invention in sectional elevation. Figures 2 and 3 are
reverse views of the piston chamber, the outer shell being removed. Figure 4
shows the piston valve and, Figure 5 is a view of the grooved and recessed end of
the piston or striker.

page_text: A, represents the piston or striker of the pneumatic tool or apparatus. This
striker is of metal and of considerable weight and fits closely in the chamber B
formed by the casing of the apparatus. The casing is composed of the upper and
.lower parts C, D screwed together. The lower part D of the casing carries the
spindle E that holds the tool F at its outer end, and this part D of the casing is
countersunk at C and again at H, the former being for the purpose of receiving the
enlarged head I of the spindle E, the latter for forming a shoulder to support the
coiled spring J that acts to return the spindle E after each stroke of the striker A
upon it in the operation of the device.
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The upper part C of the casing of the apparatus is surrounded by the shell K
and is formed with the air inlet passage a (Figure 2) and exhaust passage b
(Figures 1 and 3). It is faced off at c as shown in Figure 2, and on the opposite
side again at d, d' d' shown in Figure 3. In the flat surface c, is formed the port e
and the air inlet passage a opens in the flat surface c. The exhaust port b opens
out of the flat surface & and in the flat surface & dare formed through the casing,
the air ports ff. From flat surface c the casing C is grooved as shown at g and
again on the opposite side at g¹. The groove g leads to the port h (see full lines
Figure 1 and dotted lines Figure 3) while the groove g¹ leads to port h. From the
flat surfaces d' d' the casing C is grooved as shown at i and i. The groove i leads
to the port j, while the groove i¹ leads to the port j', both ports being shown.in full
lines in Figure 1 and in dotted lines in Figure 3.
The striker A is provided with the transversely arranged valve L and it has the
passages which reach through to the chamber that contains the valve L and
these openings coincide with or stand in the sanie plane with the ports ff. The
striker A also has the passage l'formed in it; shown in dotted lines in Figure 1.
This passage also reaches through to the valve chamber and it coincides with or
stands in the same plane with the port e made in the casing C. The striker A also
has the vertical passages m n formed in it, which reach respectively from the
chamber containing the valve L to the top and bottom of the striker, as shown in
dotted lines in Figure 1 and in full lines in Figure 5. The lower end of the
striker A is grooved as shown at o and is recessed as shown at p about the
passage and the grooves o all communicate with the recess p to facilitate
the exhaust of the air from between the lower end of the striker A and the
head I when the striker descends to deliver its blow.
The valve L is circumferentially grooved as shown at q, q, so that the valve in
its reciprocating movement caused by pressure of air entering the ports ¹¹
alternately opens and closes all the air passages through the striker A.
b.
The operation is as follows: The striker A. being in the upper position, air
admitted to the induction passage a enters the passage formed by the flat surface c
and passes through the passage e and port h¹ moving valve L to close passage k¹
and to connect passages el and m, thus admitting air above the striker A, and at
the same time the passages kf and n are connected to allow exhaust from below
the striker A through the space formed by the flat surface d and the passage
Then the air through the passage g and port h moves valve L, to close passage k to
connect passages e, l, n, to admit air below the striker and to connect passages m k¹
and f to open the exhaust from above the striker and so on alternately causing
the striker A to have a rapid reciprocating movement causing it to deliver rapid
blows upon the head I of the spindle E causing the tool F to perform its work.
Instead of using air for operating the tool, steam may be used with like results.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed I declare that what
I claim is:
1. The pneumatic tool or apparatus constructed as described and shown in the
drawings.
2. The 'striker A formed with air passages and provided with a valve combined
with a casing having air inlet and exhaust passages arranged as described..

page_text: 3. The casing C formed with air ports and grooves or passages and surrounded
by a shell as described.
4 The striker A arranged to be reciprocated by air or steam pressure combined
with the tool carrying spindle with an enlarged head as set forth.
5. The striker having slots or recesses at its lower end to facilitate exhaust as set
forth.
6. The striker A having air inlet and outlet ports or passages k, k¹ l, m, and n
and a transversely arranged valve L arranged to operate as set forth.
7. The countersink G and spindle E formed with enlarged head I combined with
striker A adapted to be reciprocated by air pressure, as set forth.
8. The striker A arranged to be reciprocated by air pressure and grooved and
recessed at its lower end, combined with the enlarged head I of the spindle E as
and for the purposes set forth.