IMPROVEMENTS IN THE MANUFACTURE OF BURGLAR-PROOF SAFES, AND IN FASTENING THE DOORS THEREOF
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by John Pinney at the Office of
the Commissioners of Patents, with his Petition, on the 23rd January
1867.
I, JOHN PINNEY, of the Town and County of Bedford, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF BURGLAR-PROOF SAFES, AND IN FASTENING THE DOORS THEREOF,"
to be as follows:-
My improvements in the manufacture of safes consist in casting them in
one operation of a proportion of soft metal, which I dispose on the inside of
the safe, and a proportion of hard and resisting metal which is disposed on
the outside, which hard metal is further hardened by chilling. For this
purpose I prepare my chill mould according to the form and size of the safe
to be made, providing it with a core to represent the form and area of the
safe, which core is of sand or loam as in ordinary. I prefer to make the
safe of about two-thirds its thickness of hard cast iron from its cheapness
and answering the purpose well, but steel or other metal that can be
hardened may be employed; the remaining third of the thickness I form of
soft metal which incorporates with the hard metal and becomes one body.
To effect this I dispose in the mould thin sheet-iron plates, separating the
mould into two spaces according to the substance of the different metals; the
mould being so prepared I pour into it at one and the same time the two
melted metals, each into its own compartment, taking care to pour them in

page_text: such proportion that the levels of the liquid in the mould will be somewhat
nearly the same throughout the pouring; so soon as the mould is filled I
withdraw the sheet-iron separating plates between the metals, and allow them
to fuse one with the other, or these plates, if made very thin, will be fused
and incorporated with the cast metals; close wire cloth may even be used for
the purpose. To give stiffness to which and to the thin plates I corrugate
them to enable them to withstand any unequal pressure of the heads of the
molten metal in the mould. In casting in the horizontal bottom of the mould
it would be necessary to pour the hard metal.first and the soft above it, while
the hard metal was still in a fluid state, or the separating diaphragm might
be suspended at points throughout its area to support the weight of soft
metal. A similar, but the reverse procedure, would take place in casting the
upper part of the cube.
A safe is thus formed having an exterior surface rendered so hard by the
chilling action as to be impenetrable to any cutting or boring tools, and of
some three-quarters of an inch more or less in thickness; the remainder of
the outside metal from its nature is also very hard and difficult to be operated
on; while the whole is incorporated with a sufficient substance of soft and
tough metal to prevent the fracture of the hard metal from blows.
The door I cast
The access to these safes I prefer to make through a round opening in the
substance of the motal, which I form with two or three steps or rebates, the
door being similarly formed, and both chilled in the edges.
in the same manner as the safe, combining soft and hard metal chilled, as
before described. The door is made slightly larger than the opening, and I
mount the door on a shaft rotated by machinery, and grind it with émery,
and so bed and fit the door in its seating. I mount this door on a hinge to
swing it into and out of the closed position as usual. On a central stud
inside the door is mounted a compound bevil and spur wheel, the bevil teeth
gear with six bevil pinions (more or less) fixed on shafts radiating from said
central wheel, such shafts being fitted in bearings on the door at their inner
ends, while the outer ends are each socketted into the head of the screw
screwed through a lug or bearing close to the circumference of the door; the
socketted parts are free to slide one on the other, but the screw is carried
round with the shaft by a pin traversing a slot.
wheel has the effect of projecting or withdrawing
and when withdrawn within the diameter of the
when projected outwards the screws enter their several screw holes formed in
the body of the safe, and not only act as bolts to prevent the door opening,
but hold it forcibly in the radial directions of the several screw bolts. The
The rotation of the central
radially the several screws,
door it is free to open, but

page_text: central wheel is rotated from the outside by a winch handle whose shaft
passes through and has a spur pinion gearing with the spur wheel before
mentioned. A disc plate formed on the spur and bevil wheel is furnished
with a suitable contrivance or notch for interlocking with the bolt of the lock
to fix or release it as may be desired by the key of the safe lock.