Improvements in and relating to Locks.
Year: 1891

page_text: Complete Specification Left, 14th Aug., 1891-Accepted, 2411 JULY
COMPLETE SPECIFICATION.
Improvements in and relating to Locks.
I, WARREN HOWARD TAYLOR, a citizen of the United States of America,
residing at Stamford, in the County of Fairfield and State of Connecticut, one of
the United States of America, 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 relates to that class of locks using sliding or pin tumblers, which
tumblers fasten a key-cylinder or roll-back to its surrounding case until the
tumblers are set by the insertion of the key, when the key-cylinder can be
revolved to operate the lock.
My present improvements relate to pin-tumblers to be used with my improved
lock of this class, in which I form a keyway with projections from its side walls
extending past its center and in which I bevel or curve the tumblers at their lower
ends upon either side of a central line transverse to the axis of the keyway. By
my present improvement, I provide an improved tumbler which has a cylindrical
bearing-surface above the keyway, but at the point where it intersects the way the
tumbler is flattened or narrowed, so that when fitted in a tumbler-chamber or
corresponding shape it cannot rotate, and being rounded or beveled on two sides of
a central line at its bottom its broad key bearing-surface will always be held in
proper position. A considerable advantage of this form of tumbler and tumbler-
chamber is that the tumbler-chamber being narrowed at its intersection with the
keyway there is less space into which a picking-tool can follow a tumbler, and also
as the material of the cylinder is not cut away to so great an extent between the
tumblers in the keyway it increases the material, or what is technically called
land," between one tumbler-chamber and another, which also adds to the difficulty
of picking. I also regard the form of tumbler here shown as advantageons in
consequence of the greater ease of manufacturing the tumbler and the cylinder
with a cylindrical bearing at some point in the length of the tumbler; but it is
obvious that the particular shape of the tumbler throughout its length, whether
rectangular or otherwise, is not material, the desirable feature being to have a
tumbler which at its key-bearing end is of less width in the direction of the length
of the keyway than at right angles thereto.
In the accompanying drawings, illustrating my invention,
Figure 1 is a front end elevation of a pin-tumbler lock, showing my improved
keyway.
Fig. 2 is a longitudinal diametrical section showing the key in place.
Fig 3 is a cross-section showing one of the tumblers and its spring in elevation.
Fig. 4 is a view of a tumbler detached.
Referring to the letters on the drawings, A indicates an escutcheon or tumbler-
case such as is ordinarily used in this class of locks. The shape of the tumbler-
case is not material, because this invention may be applied to locks of any other
class, such as cabinet-lccks, padlocks, &c.

page_text: B indicates the hub or roll-back; C, the keyway therein; D, the key: E, the
pin-tumblers, and F their springs.
The tumbler-sockets extend from the escutcheon into the roll J
sual,
and in general construction and operation my lock is similar to those of its class.
The tumblers, it will be seen, are shown as flattened at G on opposite sides and are
cylindrical at H. They might be flattened only on one side; but I prefer to
flatten them on both sides, as shown, which may be done in any usual way familiar
to metal workers.
Having now particularly described and ascertained the nature of said inven-
tion and in what manner the same is to be performed I declare that what 1
claim is-
1. In a lock, a tumbler which is cylindrical at one end and flattened at the
other end, upon which the key bears, and which flattened end is beveled or rounded
from opposite sides of a central line, so as to make a wider key bearing-surface,
substantially as described.
2. In a lock, a key-cylinder or roll-back provided with tumbler-recesses which
are cylindrical in one portion and non-cylindrical in another, so that the tumbler
which is fitted to said recesses can move at right angles to the axis of the key-
cylinder and will not revolve on its own axis, substantially as described.
Dated this 1st day of August 1891.
WARREN HOWARD TAYLOR.