Improvements in Picks.
Year: 1891

page_text: Date of Application, 4th July, 1891
Complete Specification Left, 2nd Apr., 1392-Accepted, 14th May, 1892
PROVISIONAL SPECIFICATION.
Improvements in Picks.
We JOSEPH MITCHELL of 14 Broom Close Sheffield in the County of York
Engineer and WILLIAM KIRKLEY BIRKINSHAW of Old Croft House Quarndon
Derby in the County of Derby Merchant do hereby declare the nature of our said
invention for IMPROVEMENTS IN PICKS to be as follows
This invention relates to improvements in the construction of picks, the chief
feature being in the method of securely fastening interchangeable points also. in the
extraction thereof.
In carrying this invention. into effect we cast or forge a socket with projections
of any required length according to the size of pick required, which socket is made
hollow to receive the shaft and loose points.
The said points are fitted in the socket at each end, and are slightly taper, thus
forming a wedge corresponding with the recesses in the socket, which ends project
into the eye thereof and are formed either straight or dovetailed.
The pick shaft has a steel or iron strap which is secured at its forward end by
suitable means having a dovetailed wedge groove formed down each side and let
into the top or head thereof the said dovetailed groove corresponds with the heads
of the points; the bottom portion of the groove in the strap is bevelled for the
purpose of throwing out the points when new ones are required.
In carrying this invention into effect we place the points one into each end of
the socket.leaving the dovetailed heads projecting into the eye, then pass the shaft
through the said eye, which action causes the heads of the points to slide into the
grooves of the strap, and by knocking the pick head on the ground securely fastens
the, shaft, socket, and points as one solid piece.
When the points become blunt and new ones are required to be replaced the
handle or tail end of the shaft is simply knocked on the ground and the points and
shaft are automatically separated from the socket in consequence of the bevelled
formation on, each side of the strap fixed on the head of the pick shaft.
Dated this 25th day of May 1891
WM. MCGOWAN,
Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Picks.
We, JOSEPH MITCHELL of 14 Broom Close, Sheffield, in the County of York,
Engineer, and WILLIAM KIRKLEY BIRKINSHAW of Old Croft House, Quarndon,
Derby in the County of Derby, Merchant, 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 relates to improvements in the construction of picks, the chief
feature being in the method of securely fastening interchangeable points, also in the
extraction thereof.
In carrying this invention into effect we cast or forge a socket or head with
projections of any required length according to the size of pick required, which
socket is made hollow to receive the shaft and loose points.
The said points are fitted in the sockets at each end, and are slightly taper, thus
forming a wedge corresponding with the recesses in the socket, which ends project
into the eye thereof.

page_text: The invention will be best understood by reference to the accompanying
drawings in which :-
--
Figure 1 is an elevation of the complete apparatus.
Figure 2 a section of the same.
Figure 3 a cross section and
Figure 4 an edge view of the shaft with the strap in position.
Like letters represent like parts throughout the drawings.
A is the wooden shaft or handle of the pick, B the strap preferably rivetted to
the shaft by rivets B1 and B2 and securely fitted upon the end of it. This strap is
provided with grooves C in its edges tapering so that the bottoms of the grooves C³
are nearer together at the extremity of the shaft or opposite the blades E than
they are at their other ends adjacent to the rivet B; this is clearly shown in
Figure 2. The ends of the grooves may be closed at B3 if desired (or they may be
carried through to the top as shown in dotted lines in Figure 2) and enlarged
recesses may be formed at C₁ to accommodate the blades which in use become
forced too far into their sockets. The socket or head D is provided with an eye D³
for the reception of the shaft and strap and with sockets D2 for the reception of the
blades E. The eye is tapered to agree with the outside faces of the strap B which
are tapered in the reverse direction to the taper of the grooves C so as to prevent
the sooket or head from working off the end of the shaft. The blades E and
sockets D may be tapered as shown in the drawings so that with use the blades
become firmly fixed in the socket or head D.
In using this apparatus the shaft with the strap secured to it is placed in the
socket and secured by striking on the end as will be well understood and the
blades E are inserted in their sockets and readily fixed by a blow on the end. The
inner ends of the blades project beyond the inner ends of the sockets in which
they fit and enter the grooves C or the recessed portions C¹ thereof and to remove
the blades all that is necessary is to hold the pick by the socket or head strike the
free end of the handle upon the ground or upon some solid substance when the head
will slide down the shaft and the ends E¹ of the blades coming in contact with the
inclined bottoms of the grooves C will be forced out of their sockets while the head
will be freed from the shaft.
The grooves C having to stand the wear of repeatedly forcing out the blades E
may have their bottom faces hardened or these may be protected by suitable pieces
of hard metal let in for the purpose; or the whole strap may be made hard if
desired or the grooves may be chilled in casting; the grooves C as shown in
Figure 4, lie parallel with the axis of the shaft but they may if desired be set
obliquely thereto to a slight extent for the purpose of jamming or helping to fix
the blades E. In most cases however the groove will be formed as indicated in the
drawings.
As previously described the strap B has been provided with grooves C but it
will be observed that the same result may be attained by merely providing the
inclined faces C² without the groove edges these portions of the strap being merely
flattened and properly inclined.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that
what we claim is :-
1. In a pick head the combination with a socket or head such as D carrying the
blades of a strap such as B into which the blades E project. substantially as
described and illustrated in the accompanying drawings.
2. In a pick head a strap such as B having tapered grooves such as C into which
the ends of the blades project substantially as described and illustrated in the
accompanying drawings.
3. In a pick head the employment of inclined faces such as C³ for the purpose of
driving out the blades.

page_text: 4. In a pick head the method of driving out extracting or expelling the blades
by means of fixed inclined faces substantially as described.
5. In a pick a socket or head such as D having an eye such as D³ into which the
inner ends of the blades project substantially as described and illustrated in the
accompanying drawings.
6. In a pick a strap such as B having faces inclined in opposite directions those
in one direction serving to retain the pick head upon the shaft and those in the
other direction serving to extract or expel the blades substantially as described.
Dated this 1st day of April 1892.
JOSEPH MITCHELL.
W. K. BIRKINSHAW.
W. P. Thompson & Boult,
Agents for the Applicants.
JOSEPH MITCHELL.
W. K. BIRKINSHAW.
W. P. Thompson & Boult,
Agents for the Applicants.