Improvements in Door Locks.
Year: 1887

page_text: Improvements in Door Locks.
We, GEORGE BROWN UNDERWOOD, Lockmaker, and, DUNCAN ALBERT DOBIE,
Medical Student, both of the City of Toronto, in the Province of Ontario, in the
Dominion of Canada, hereby declare the nature of our invention for "IMPROVEMENTS
IN DOOR LOCKS," and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
Our invention consists in providing the trippet and latch bolt with convergent faces,
whereby the bolt will be expelled during the frictional contact of the converging
faces; also, in the combination of a gravitating lever and gravitating weight to
project the bolt, and a dog operated by a key to lock the bolt when projected; also,
in gravitating levers to depress gravitating tumblers after the tumblers have been
raised by a key in shooting the bolt; also, in a slide which simultaneously closes the
key holes and engages the gravitating weight to lock the bolt independently of
the key.
Fig. 1, is a plan of the interior of our improved lock, showing position when the
bolt is projected.
Fig. 2, is a like view showing the position of parts when the bolt is retracted.
Fig. 3, is a like view, the gravitating weight and tumblers being removed to show
the parts below.
Fig. 4, is a partial plan of the interior of the lock, showing the dog and gravitating
lever engaged to lock the bolt.
Fig. 5, is a detail showing the position of the slide when covering the key holes
and engaging the gravitating weight.
Fig. 6, is a plan of the underside of the gravitating weight.
Fig. 7, is a plan of the underside of the gravitating lever.

page_text: .
Fig. 8, is a plan of the key, 'and,
Fig. 9, is a plan of the interior of a lock, showing modification in the gravitating
weight applied to depress the tumblers.
1, is the lock case, the cover-plate removed: 2, are holes for screws to fasten the
lock to a door, and 3 a post provided with a screw-tapped hole in the end to fasten
the cover-plate upon the case, by a screw in the usual manner.
5, is the lock-bolt sliding within the case through an opening in the front rim,
and 6, the spindle socket having a triangular shaped trippet 7 formed integrally there-
with. Bolt 5 has a transverse notch 8, to receive the trippet flatwise, and is bifurcated
at the heel to straddle the spindle socket, and allow of retraction of the bolt when the
trippet is rocked by a knob spindle in the usual manner.
The forward end of notch 8 has two converging sides 9, 9, which coincide with the
converging sides 10, 10, of the trippet, so that after the bolt is retracted in the usual
manner by the trippet, the bolt will be expelled by the converging faces of the bolt
and trippet having frictional contact.
11, is an S-shaped gravitating lever hung on a post 12 cast with the lock case. The
shorter end of the lever engages with the heel of the bolt, and the free end is provided
with a notch 13 to receive the end of a dog 14 which is reciprocated by a key, Fig. 8,
admitted through the key hole 15. The dog is provided with a post 16, and has
slots 17, 18, to admit posts 19, 20, cast integrally with the case, and guide the
reciprocation of the dog.
Post 20, projects some distance through the slot in the dog, and on said post is
hung one or more flat tumblers 21, which are provided with slots which bear upon
post 16 of the dog, so that by turning the key, the tumblers will be raised and the
dog shot into notch 13 in lever 11, to lock bolt 5.
22, is a gravitating weight hung on post 12, and has a projection 23, on the under-
side, see Fig. 6, to bear upon a portion of the edge of lever 11, and said weight has a
tit 24, to bear against the top of the tumblers, so that by the gravitation of the
weight, lever 11, will be depressed to throw out bolt 5, and tumblers 21, will be
depressed to offer resistance to the turning of the key.
25, is a slide, having faces 26, at opposite sides to cover the key holes in the sides
of the lock case to prevent entrance of a key. One end of the slide is provided with
a raised step 27, which enters a notch 28 in the gravitating weight, and prevents the
weight rising when the slide is adjusted to cover the key holes. By locking the
weight the gravitating lever 11 is prevented from rising, and bolt 5 becomes locked.
The slide is reciprocated by a lever 29 journalled in the lock case, and said lever has
an arm 30 projecting through a slot in the rim of the lock case to reciprocate the slide
from the outside of the lock case.
The gravitating weight 22, if desired, may be in one or more pieces, preferably
corresponding in number to the number of tumblers, and the tumblers may be hung
to the dog at the end farthest from the gravitating lever 11.
In Fig. 9, we show a lock in which the spindle knob and socket are dispensed with,
and in such case the tumblers will be hung on a post 20, integral with the lock case,
and passing through a slot 18, in the bolt, to allow the bolt to have the reciprocating
movement, and above the tumblers is hung on a post 12, of the lock case, a series
of levers 11, which depress the tumblers after being raised by the key to shoot
the bolt.
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. The combination of the bolt 5 having a notch 8 provided with converging
sides 9, 9, and the spindle socket 6 having a trippet 7 provided with con-
verging sides 10, 10, whereby the bolt is expelled when the converging sides of the
bolt and trippet are in frictional contact, substantially as set forth.
2. The combination with bolt 5 and spindle socket 6 having. trippet 7, of the

page_text: gravitating lever 11, gravitating weight 22, dog 14 and tumblers 21, as set forth for
the purpose described.
3. The slide 25, in combination with the gravitating lever 11 and gravitating
weight 22, to simultaneously lock the bolt and close the key holes, as set forth.
4. The gravitating lever or levers 11, pivoted to the lock case, in combination with
tumblers 21, and bolt 5, to give increased resistance to the key, as set forth.
5. The combination with the lock case 1, having posts 12, 16, 19, and 20, and bolt 5,
of the tumblers 21, and gravitating lever or levers 11, whereby the levers depress the
tumblers, as set forth.
6. The combination with the lock case 1, having posts 12, 19, and 20, and bolt 5
having stud 16, and-slots 17, 18, of the tumblers 21 and gravitating lover 22 pivoted
as set forth.
7. The combination with the lock case 1, of the gravitating levers 11, tumblers 22,
and bolt 5, as set forth.